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DPC latency unacceptably high, causing jerky performance and driver issues RRS feed

  • General discussion

  • ... among many other Windows 8 problems I've run into so far ...

    DPC latency, which (for the uninitiated) basically is how fast the "needs to be processed as fast as possible" tasks in a PC are run. Deferred procedure calls (DPCs) allow programs to "queue" actions to be done quickly in the processor scheduler, and they hang the whole computer until they get processed. For example, drawing a video frame on a screen needs to be done as soon as the data is ready and the frame time is reached. Playing music needs to keep the audio buffer filled in real-time. Moving the cursor is done in real-time as well - the mouse driver uses a DPC to move the cursor around.

    That's why DPC latency is important. If there's a hardware driver using a DPC outside of MS's specs for drivers (which say that the DPC shouldn't be used to transfer data, and to return as quickly as possible - e.g. to signal "hey, go get the data")., DPC latency spikes can cause laggy, slow performance, audio glitches/stuttering, etc.

    The only tool I'm aware of to test DPC latency is literally called "DPC Latency Checker" (search it, it's very popular).

    On Windows 8, it reports DPC latency of 1000us (1ms) at the very lowest. It never reaches below 1000us, ever. It regularly spikes up in the 2-3ms (2,000-3,000us) range, and often spikes into the 20-30ms (!) range during processing. When I started a VMWare machine from a network (wireless) location, every single check came back 20-50+ms. WOW.

    However, to test the cause, I popped in a new hard drive and installed Windows 7, clean install, with just basic Windows Update drivers installed (video, net, etc). DPC latency was down to a more usual level - between 200 and 500us, with occasional spikes to 1-2ms.

    I went back and dug through Windows 8, disabling EVERY device in the system - sound, modem, media cards, USB, network (wireless and wired), display, etc., as well as listing all kernel drivers and "sc stop"'ing the ones I saw were third-party. Nothing, nothing at all, reduced the DPC latency. Tried uninstalling Dell QuickSet, as I found that interfacing with the Dell subsystems tends to add DPC lag. Also tried disabling processor power management ("update driver" on CPU, to "Processor" driver instead of "Intel Processor"). Nothing fixed it. Nothing even affected it.

    Can someone else out there running Windows 8 run DPC Latency Checker and see if they have the same problem?

    My setup:

    Dell XPS M1710
    Intel Core Duo T2400 @ 1.83GHz
    Intel i945PM northbridge/82801GHM (ICH7-M) southbridge
    2GB RAM (DDR2 dual-channel), 120gb HDD (SATA)
    nVidia GeForce Go 7900 GS (256mb)*
    Intel 4965AGN wireless adapter, Broadcom NetXtreme 57xx LAN
    SigmaTel audio, O2Micro Smartcard reader, Ricoh 1394 and Flash media interface, Synaptics touchpad, Conexant HDA modem
    * - nVidia GPU doesn't have a driver available on Windows Update, but the driver from the Windows Update Catalog for Windows 7 and VEN_10DE&DEV_0298 works flawlessly.
    Sunday, March 11, 2012 10:47 AM

All replies

  • Run the Intel chipset update utility. It may improve communication. They may not be "in the box" of the CP as they are in the RTM of Win 7.

    http://downloadcenter.intel.com/SearchResult.aspx?lang=eng&ProductFamily=Chipsets&ProductLine=Laptop+Chipsets&ProductProduct=Mobile+Intel%c2%ae+945+Express+Chipset+Family

    Nvidia supported the gpu with the 179.48 beta driver: http://www.nvidia.com/object/geforce_notebook_winvista_win7_179.48_beta.html

    so, the 179.67 from the Update Catalog is later and the best option.

    There's not much you can do about the audio drivers.

    Looks like you are setup great, except for the chipset .inf.

    I would also recommend using the 32-bit OS on that hardware.

    Sunday, March 11, 2012 2:19 PM
  • Start the Windows ADK setup and select the Windows Performance Tool

    and install it.

    Now run the command promt (cmd.exe) with admin rights and run this:

    xperf -on latency -stackwalk profile -buffersize 1024 -MaxFile 256 -FileMode Circular && timeout -1 && xperf -d DPC_Interrupt.etl

    Now capture 30s while you have the issue, go backt cmd and press a key to stop tracing.

    Now run

    xperf -I DPC_Interrupt.etl -a dpcisr > dpc.txt

    to dump the data from the trace into a text file.

    Open the DPC.txt and check which driver causes the 1000µs spikes. If this is too complicated, compress the DPC_Interrupt.etl as 7z/RAR and upload it to your SkyDrive and post a link here.

    I'll look at it and try to find the cause.


    André


    "A programmer is just a tool which converts caffeine into code"

    Sunday, March 11, 2012 6:51 PM
    Answerer
  • That's definitely the most useful set of replies I've ever had from someone in the MS forum - thanks!! I'm kinda used to seeing "try rebooting" style answers ;)

    I installed the chipset software, but as expected (Intel writes that the only thing the chipset installer does is put correct names on the chipset components, sadly), it didn't have an effect on the DPC problem.

    DPC Latency

    So I ran the trace. Sadly, I didn't find anything standing out... ndis.sys was the only thing that looked a bit out of line with its handful of 512-1024 and 2048-4096usec entries.

    DPC log (.txt) - just sitting idle with the trace CMD window open

    Out of curiosity, I tried putting some network activity in the background - extracting a 2gb archive with WinRAR from my server (Windows Home Server 2011) to the system desktop, with a 5GHz "N" wireless connection moving at ~10MB/s (if it doesn't get hung up in latency). DPC latency shot through the roof.

    DPC latency with network activity

    Even the mouse cursor started to get jerky...

    But it all seems to be related to ndis.sys, which has the highest latency spikes in the log...

    Monday, March 12, 2012 1:24 AM
  • Just realized how large that ETL file is... so I guess it would be more useful than a watered-down TXT report ;)

    Here's the ETL of the trace with net activity. :)

    Monday, March 12, 2012 3:58 AM
  • The Intel(R) Wireless WiFi Link 4965AGN driver (NETwLv32.SYS) casues the issues:

    I see you use the driver version 13.4.0.139. So try to update the driver to this version:

    http://downloadcenter.intel.com/Detail_Desc.aspx?agr=Y&DwnldID=20790&lang=eng

    The driver is for Windows 7, but should work in Windows 8, too.
    Give it a try an tell me the result.

    André


    "A programmer is just a tool which converts caffeine into code"

    Monday, March 12, 2012 1:24 PM
    Answerer
  • I tried that, but the driver is mis-labeled and half-baked - the driver INF provided with the 14.x versions only includes a text description for the 4965AGN, but no actual installer section for it (VEN_8086&DEV_4229). So I'd have to hack the INF to get it to install. Kinda frustrating since the driver provided with Windows is so old (and has bugs like this). Maybe that could be reported to Intel somewhere?

    I also did another trace with the system totally idle, which still produces >1ms (1000usec) DPC latency every-single-time like clockwork (I haven't yet seen a single "green" bar in Windows 8 with the DPC latency tool)...

    http://dl.dropbox.com/u/35284720/postfiles/DPC_Interrupt_Idle.rar


    The key concern here is that the DPC latency is still >1000usec even with:

    - all non-system devices disabled (USB, modem, sound, network, media, etc)
    - every core networking service stopped that can be stopped (except NDIS and TCPIP themselves), using "sc" and ServiWin
    - all non-MS services and drivers stopped

    That's the frustrating part. Not a single damn thing could possibly be running (including the network drivers), and I still consistently get >1000usec DPC times. No CPU throttling either (checked and tweaked that with RMClock). All the while, Windows 7 on this thing just churns along with mostly normal DPC times, even with the old Intel drivers *and* bad power management settings that cause high DPC latency. It's like there's a timed DPC that's causing these 1000usec delays on a timer...

    • Edited by FalconFour Monday, March 12, 2012 4:34 PM
    Monday, March 12, 2012 4:27 PM
  • I checked the new tarce and found some ATAPort driver spikes (IdePortCompletionDpc). This happens because your WD HDD and your Sony DVD Burner run in IDE mode. Try to activate AHCI and look if this fies the issue.

    "A programmer is just a tool which converts caffeine into code"

    Monday, March 12, 2012 6:53 PM
    Answerer
  • Oh, I would beat down the doors of Intel to fix that if I could, but the ICH7-M doesn't support AHCI. I'm stuck with IDE.

    Does IDE poll at 1-second intervals? That could indeed explain the >1000usec DPC delays, but it'd be awful odd if it happens to be synced up every time. I mean, I'm getting >1000usec DPCs no matter what time of day, what condition, what place, state, drivers, or anything at all, it has never ever returned a result lower than 1000usec. Maybe something is polling at 1-second intervals... maybe I should try a different hard drive or something? Is ATAPort the only thing you see hanging for 1ms for the whole duration (not just a spike or two, but like clockwork every single second)? 

    Monday, March 12, 2012 11:56 PM
  • My T61 support AHCI. But things like. On Windows 8 DPC latency level is 1000us, but on Windows 7 — 500us.

    Tuesday, March 13, 2012 9:18 AM
  • Does IDE poll at 1-second intervals? That could indeed explain the >1000usec DPC delays, but it'd be awful odd if it happens to be synced up every time.


    no, the IDE DPCs only happen sporadic. I can see that RMCLock causes every 1s some CPu usage, so maybe ths causes the "hangs". Run Win8 without this old tool.

    "A programmer is just a tool which converts caffeine into code"

    Tuesday, March 13, 2012 12:34 PM
    Answerer
  •  On Windows 8 DPC latency level is 1000us, but on Windows 7 — 500us.

    Do the same that I told to falcon4, install the ADK/WPT and run the command.

    "A programmer is just a tool which converts caffeine into code"

    Tuesday, March 13, 2012 12:35 PM
    Answerer
  • I can verify the exact same behavior.

    Comparing Windows 7 Ultimate x64 and Windows 8 CP x64 in nearly identical VMware virtual machines (one at a time) on the same host, the minimum on the Windows 8 CP is some 600 microseconds longer than in Windows 7.

    Windows 7 x64:

     

    Windows 8 CP x64:

      

    I don't know how running the machine in VMware affects this, and I don't have Windows 8 on real hardware yet, but I do see that the host Windows 7 x64 system runs with a minimum latency of under 100 microseconds.  The difference between the two VM measurements does seem significant.

    I have been wondering if it's possible the Windows 8 CP build is not fully performance-optimized.  Might make sense to instrument it with a lot of debugging aids enabled, no?  Better to find out about system problems now than after a fully optimized build is RTM and you get back only "it crashed", rather than "buffer overflow in module xxxx at location yyyy".  This observation kind of fits that theory.

     

    -Noel


    Detailed how-to in my eBook:  
    In development:

    Configure The Windows 7 "To Work" Options
    Configure The Windows 8 "To Work" Options

    Saturday, March 17, 2012 9:42 PM
  • Noel,

    also install the ADK/WPT and run the xperf trace.

    André


    "A programmer is just a tool which converts caffeine into code"

    Sunday, March 18, 2012 11:19 AM
    Answerer
  • I've had the exact same issue on my Thinkpad X200 tablet /w Windows 8 CP.  Like further in the thread, the intel driver (and ndis.sys) stood out as the problem initially, but after disabling the network driver, both acpi.sys and storport.sys stood out with DPC issues.

    As I have Win7 dual booting, where the issue is not present, I then went as far as to transfer over the exact same drivers (well the third-party ones like the Intel ones) to Win8.  There was no change.

    I attempted the normal guess work like BIOS updates, switching AHCI to IDE (amusingly the "automated repair" in Win8 still can't handle that change automatically), and disabling as much as I could in Device Manager.  I haven't bothered to reinstall the developer preview to see if there were possible DPC issues there, but I had no issues with audio or video playback prior to the consumer preview build.  At this point, Win8 CP can't even play a basic DVD properly.

    Certainly, I'm pleased I'm not the only one with this issue as it seems like a bug with certain hardware.


    Jonathan Kay, MSN Messenger/Windows Messenger MVP

    Monday, March 26, 2012 6:36 PM
  • can you also make a xperf trace and upload the trace here?

    "A programmer is just a tool which converts caffeine into code"

    Monday, March 26, 2012 9:05 PM
    Answerer
  • Sorry I haven't gotten back to doing this - simply too much else on my plate lately.  I still will try to find some more time.

    Notably in my case I've seen no downsides - Windows 8 has had no problems whatsoever playing streaming audio, videos, etc.

     

    -Noel


    Detailed how-to in my eBook:  
    In development:

    Configure The Windows 7 "To Work" Options
    Configure The Windows 8 "To Work" Options

    Tuesday, March 27, 2012 7:18 PM
  • Hi Noel,

    have you made the trace?

    André


    "A programmer is just a tool which converts caffeine into code"

    Sunday, April 1, 2012 8:35 PM
    Answerer
  • Unfortunately no, not yet - sorry.  I have continued to be overwhelmed with more mundane issues, as well as testing the new Photoshop CS6 beta (and my products with it).

    As I mentioned before, I've experienced no particular issues with my Win 8 VM that indicate this is a real problem, and as well I have observed that other VMs (e.g., Windows 7) do tend to show a significantly higher latency than when the same OS is run on the hardware directly.  I have little idea what specific hoops VMware must jump through, but no doubt there's some real complexity at work there chewing up microseconds.

    -Noel


    Detailed how-to in my eBook:  
    In development:

    Configure The Windows 7 "To Work" Options
    Configure The Windows 8 "To Work" Options

    Sunday, April 1, 2012 9:20 PM
  • My money's on a Windows 8 debug hook issue or some such issue related to pre-release tracking. I gave up on Windows 8 and went back to Windows 7. Same PC, same *exact* software and driver configuration (I made sure to match it exactly using the same installers)... and DPC latency is much closer to sanity, below 1ms/1000usec.

    (So it's not related to RMClock, which I was using to diagnose a throttling issue caused by a low-wattage AC adapter, which was not the cause either.)

    As I said before, I stopped *every*, *single* driver and service in the system under Windows 8 (at service/driver level, not Device Manager), and the DPC latency never went under 1000usec. So...

    Sunday, April 1, 2012 10:47 PM
  • I got the same issue here.

    Even tried disable the NIC.

    I've run the trace but it only said unknown.

    DPC Latency Checker never goes under 1000 µs.

    LatencyMon lists some drivers with high latency.

    _________________________________________________________________________________________________________
    CONCLUSION
    _________________________________________________________________________________________________________
    Your system appears to be having trouble handling real-time audio and other tasks. You are likely to experience buffer underruns appearing as drop outs, clicks or pops. The cause of the problem is not immediately apparent.
    LatencyMon has been analyzing your system for 0:04:52 (h:mm:ss)


    _________________________________________________________________________________________________________
    System Information
    _________________________________________________________________________________________________________
    Computer name:                                        WINDOWS8
    OS version:                                            , 6.2, build: 8250
    CPU:                                                  GenuineIntel Intel(R) Core(TM)2 Quad CPU    Q6600  @ 2.40GHz
    Logical processors:                                   4
    RAM:                                                  4294033408 total
    VM:                                                   2147352576, free: 1950199808


    _________________________________________________________________________________________________________
    CPU SPEED
    _________________________________________________________________________________________________________
    Reported CPU speed:                                   2405 MHz
    Measured CPU speed:                                   2388 MHz

    Note: reported execution times may be calculated based on a fixed reported CPU speed. Disable variable speed settings like Intel Speed Step and AMD Cool N Quiet in the BIOS setup for more accurate results.


    _________________________________________________________________________________________________________
    MEASURED KERNEL TIMER LATENCIES
    _________________________________________________________________________________________________________
    Highest measured kernel timer latency (µs):           2065.4639


    _________________________________________________________________________________________________________
    MEASURED SMIs AND CPU STALLS
    _________________________________________________________________________________________________________
    Highest measured SMI routine or CPU stall (µs)        11.6800


    _________________________________________________________________________________________________________
    REPORTED DPCs
    _________________________________________________________________________________________________________
    Highest DPC routine execution time (µs):              415.1750
    Driver with highest DPC routine execution time:       ndis.sys - NDIS 6.30 driver, Microsoft Corporation

    Highest reported total DPC routine time (%):          0.2475
    Driver with highest DPC total execution time:         USBPORT.SYS - USB 1.1 & 2.0 Port Driver, Microsoft Corporation

    Total time spent in DPCs (%)                          0.9443

    DPC count (execution time <250 µs):                   1135117
    DPC count (execution time 250-500 µs):                0
    DPC count (execution time 500-999 µs):                7
    DPC count (execution time 1000-1999 µs):              0
    DPC count (execution time 2000-3999 µs):              0
    DPC count (execution time >=4000 µs):                 0


    _________________________________________________________________________________________________________
     REPORTED ISRs
    _________________________________________________________________________________________________________
    Highest ISR routine execution time (µs):              194.7629
    Driver with highest ISR routine execution time:       dxgkrnl.sys - DirectX Graphics Kernel, Microsoft Corporation

    Highest reported total ISR routine time (%):          0.2292
    Driver with highest ISR total time:                   dxgkrnl.sys - DirectX Graphics Kernel, Microsoft Corporation

    Total time spent in ISRs (%)                          0.3158

    ISR count (execution time <250 µs):                   274999
    ISR count (execution time 250-500 µs):                0
    ISR count (execution time 500-999 µs):                0
    ISR count (execution time 1000-1999 µs):              0
    ISR count (execution time 2000-3999 µs):              0
    ISR count (execution time >=4000 µs):                 0


    _________________________________________________________________________________________________________
     REPORTED HARD PAGEFAULTS
    _________________________________________________________________________________________________________
    Process with highest pagefault count:                 none

    Total number of hard pagefaults                       704
    Hard pagefault count of hardest hit process:          236
    Highest hard pagefault resolution time (µs):          377862.6230
    Total time spent in hard pagefaults (%):              0.3647
    TODO: Number of processes hit:                        0


    _________________________________________________________________________________________________________
     PER CPU DATA
    _________________________________________________________________________________________________________
    CPU 0 ISR count:                                      69053
    CPU 0 ISR highest execution time:                     194.7629
    CPU 0 ISR total execution time:                       982372.5467
    CPU 0 DPC count:                                      506164
    CPU 0 DPC highest execution time:                     415.1750
    CPU 0 DPC total execution time:                       3768410.9338
    _________________________________________________________________________________________________________
    CPU 1 ISR count:                                      68268
    CPU 1 ISR highest execution time:                     175.3783
    CPU 1 ISR total execution time:                       869430.5730
    CPU 1 DPC count:                                      145576
    CPU 1 DPC highest execution time:                     380.3875
    CPU 1 DPC total execution time:                       1986394.3072
    _________________________________________________________________________________________________________
    CPU 2 ISR count:                                      68548
    CPU 2 ISR highest execution time:                     186.4740
    CPU 2 ISR total execution time:                       977350.2586
    CPU 2 DPC count:                                      88791
    CPU 2 DPC highest execution time:                     244.5792
    CPU 2 DPC total execution time:                       1989178.3534
    _________________________________________________________________________________________________________
    CPU 3 ISR count:                                      69130
    CPU 3 ISR highest execution time:                     169.3683
    CPU 3 ISR total execution time:                       868427.4500
    CPU 3 DPC count:                                      394593
    CPU 3 DPC highest execution time:                     235.9640
    CPU 3 DPC total execution time:                       3312143.1954
    _________________________________________________________________________________________________________

    • Edited by Andreasvb Monday, April 2, 2012 2:17 AM
    Monday, April 2, 2012 1:58 AM
  • the values are ok. Only some USBport DPCs reahc the 1000µs value.

    But the hard pagefaults are too high. Do you have Superfetch disabled?


    "A programmer is just a tool which converts caffeine into code"

    Monday, April 2, 2012 5:55 PM
    Answerer
  • SuperFetch is enabled.

    I made a new sample, computer up for about a day.

    Thanks for looking on the problem, really annoying when everything skips.

    _________________________________________________________________________________________________________
    CONCLUSION
    _________________________________________________________________________________________________________
    Your system appears to be having trouble handling real-time audio and other tasks. You are likely to experience buffer underruns appearing as drop outs, clicks or pops. One or more DPC routines belonging to a driver running in your system appear to be executing for too long. At least one detected problem appears to be network related. You may have to disable wireless adapters to get better results.
    LatencyMon has been analyzing your system for 0:05:30 (h:mm:ss)


    _________________________________________________________________________________________________________
    System Information
    _________________________________________________________________________________________________________
    Computer name:                                        WINDOWS8
    OS version:                                            , 6.2, build: 8250
    CPU:                                                  GenuineIntel Intel(R) Core(TM)2 Quad CPU    Q6600  @ 2.40GHz
    Logical processors:                                   4
    RAM:                                                  4294033408 total
    VM:                                                   2147352576, free: 1920950272


    _________________________________________________________________________________________________________
    CPU SPEED
    _________________________________________________________________________________________________________
    Reported CPU speed:                                   2405 MHz
    Measured CPU speed:                                   2406 MHz

    Note: reported execution times may be calculated based on a fixed reported CPU speed. Disable variable speed settings like Intel Speed Step and AMD Cool N Quiet in the BIOS setup for more accurate results.


    _________________________________________________________________________________________________________
    MEASURED KERNEL TIMER LATENCIES
    _________________________________________________________________________________________________________
    Highest measured kernel timer latency (µs):           107309.1968


    _________________________________________________________________________________________________________
    MEASURED SMIs AND CPU STALLS
    _________________________________________________________________________________________________________
    Highest measured SMI routine or CPU stall (µs)        11.4937


    _________________________________________________________________________________________________________
    REPORTED DPCs
    _________________________________________________________________________________________________________
    Highest DPC routine execution time (µs):              107216.6819
    Driver with highest DPC routine execution time:       ndis.sys - NDIS 6.30 driver, Microsoft Corporation

    Highest reported total DPC routine time (%):          0.3211
    Driver with highest DPC total execution time:         nvlddmkm.sys - NVIDIA Windows Kernel Mode Driver, Version 296.17 , NVIDIA Corporation

    Total time spent in DPCs (%)                          1.3486

    DPC count (execution time <250 µs):                   1454120
    DPC count (execution time 250-500 µs):                0
    DPC count (execution time 500-999 µs):                50
    DPC count (execution time 1000-1999 µs):              1
    DPC count (execution time 2000-3999 µs):              0
    DPC count (execution time >=4000 µs):                 0


    _________________________________________________________________________________________________________
     REPORTED ISRs
    _________________________________________________________________________________________________________
    Highest ISR routine execution time (µs):              187.1775
    Driver with highest ISR routine execution time:       dxgkrnl.sys - DirectX Graphics Kernel, Microsoft Corporation

    Highest reported total ISR routine time (%):          0.3642
    Driver with highest ISR total time:                   dxgkrnl.sys - DirectX Graphics Kernel, Microsoft Corporation

    Total time spent in ISRs (%)                          0.5256

    ISR count (execution time <250 µs):                   612802
    ISR count (execution time 250-500 µs):                0
    ISR count (execution time 500-999 µs):                0
    ISR count (execution time 1000-1999 µs):              0
    ISR count (execution time 2000-3999 µs):              0
    ISR count (execution time >=4000 µs):                 0


    _________________________________________________________________________________________________________
     REPORTED HARD PAGEFAULTS
    _________________________________________________________________________________________________________
    Process with highest pagefault count:                 none

    Total number of hard pagefaults                       1213
    Hard pagefault count of hardest hit process:          566
    Highest hard pagefault resolution time (µs):          1089159.8033
    Total time spent in hard pagefaults (%):              0.8683
    TODO: Number of processes hit:                        0


    _________________________________________________________________________________________________________
     PER CPU DATA
    _________________________________________________________________________________________________________
    CPU 0 ISR count:                                      152313
    CPU 0 ISR highest execution time:                     154.7887
    CPU 0 ISR total execution time:                       1813016.7093
    CPU 0 DPC count:                                      575309
    CPU 0 DPC highest execution time:                     20307.7347
    CPU 0 DPC total execution time:                       5688969.1740
    _________________________________________________________________________________________________________
    CPU 1 ISR count:                                      153236
    CPU 1 ISR highest execution time:                     187.1775
    CPU 1 ISR total execution time:                       1646156.6270
    CPU 1 DPC count:                                      548002
    CPU 1 DPC highest execution time:                     95010.3355
    CPU 1 DPC total execution time:                       5180977.6016
    _________________________________________________________________________________________________________
    CPU 2 ISR count:                                      154209
    CPU 2 ISR highest execution time:                     157.3708
    CPU 2 ISR total execution time:                       1851564.2893
    CPU 2 DPC count:                                      160099
    CPU 2 DPC highest execution time:                     107216.6819
    CPU 2 DPC total execution time:                       3693821.8190
    _________________________________________________________________________________________________________
    CPU 3 ISR count:                                      153044
    CPU 3 ISR highest execution time:                     159.9193
    CPU 3 ISR total execution time:                       1635154.1738
    CPU 3 DPC count:                                      170769
    CPU 3 DPC highest execution time:                     54243.3218
    CPU 3 DPC total execution time:                       3257943.7621
    _________________________________________________________________________________________________________

    Monday, April 2, 2012 6:19 PM
  • install the ADK/WPT and run the xperf commands. Zip the DPC_Interrupt.etl and upload it.

    "A programmer is just a tool which converts caffeine into code"

    Tuesday, April 3, 2012 6:10 PM
    Answerer
  • Couldn't find any process/driver other than "Unknown", that's why I used the other program.

    Here's the file, http://snell.hest.nu/DPC_Interrupt.7z

    Appreciated.

    Tuesday, April 3, 2012 8:58 PM
  • You have some DPC spikes caused by the functions IppTimeout and IppPathSetTimeout from the tcpip.sys. Do you have internet connection issues?


    "A programmer is just a tool which converts caffeine into code"



    Tuesday, April 3, 2012 9:41 PM
    Answerer
  • No, none at all.

    http://www.speedtest.net/result/1873805704.png

    It worked excellent in Windows 7, nothing is changed as I made an upgrade to Windows 8.

    Any idea what I can do to reduce the DPC on tcpip.sys?

    I have the following properties for my NIC (Marvell Yukon 88E8056 PCI-E Gigabit Ethernet Controller):

    Driver Date: 2011-10-11

    Driver Version: 12.0.9.3

    Energy Star: Enabled
    Flow Control: Rx & Tx Enabled
    Interrupt Moderation: Enabled
    IPv4 Checksum Offload: Rx & Tx Enabled
    Jumbo Packet: 1514 Bytes
    Large Send Offload (IPv4): Enabled
    Log Status Messages: Warnings
    Max IRQ per Sec: 5000
    Network Address: N/A
    Receive Buffers: 256
    Speed & Duplex: 100Mbps Full Duplex
    TCP Checksum Offload (IPv4): Rx & Tx Enabled
    Transmit Buffers: 256
    UDP Checksum Offload (IPv4): Rx & Tx Enabled
    Wake From Shutdown: On
    Wake on magic packet: Enabled
    Wake on pattern match: Enabled
    Wake-Up Capabilities: Magic Packet & Pattern



    • Edited by Andreasvb Tuesday, April 3, 2012 10:10 PM
    Tuesday, April 3, 2012 10:08 PM
  • Just to bump this up in hope that the final product is not like this and this is all due to debugging hooks as mentioned.

    I have the same issue on totally different high-end desktop hardware (Asus Rampage/Sandy-E).

    Using DPC Latency checker in Win7 latency is reported below 100us, while in Win8 it is 1000us+.
    Another tool LatencyMon reports in Win8 around 200us with spikes to 1000us approx each second, kinda more precise but indicates that there is a problem.

    Highest reported drivers were Kernel, nVidia and the tool itself. But there were alot of page faults.

    I reinstalled Win7 back just because of this, however if there is anything that you want me to test, I would be willing to reinstall Win8 on another partition.

    Saturday, April 7, 2012 11:28 AM
  • also make a xperf trace and upload it.

    "A programmer is just a tool which converts caffeine into code"

    Sunday, April 8, 2012 4:34 PM
    Answerer
  • I have the same problem, tested on:

    HP ENVY 17 I7 QM720
    HP ENY 14  I7 QM740
    MacBook PRO 2011 I7  sandy bridge, bootcamped
    Mac MINI i5 sandy bridge bootcamped
    ASUS G73H

    All machines with 1000us to 1200us
    With soundcard MOTU ULTRALITE MK3, I can work correctly due drivers of MOTU are incredible good and work ok with that latency, but with any other sound card I tested , is just impossible.

    I search on forums and see is common problem for high amount of users.
    Is incredible again Microsoft  team not work in this deeply.
    Microsoft is loosing again the great chance of catch mac pro audio users.
    Somebody from MS WIN8 team should take this issue seriously, and fix ASAP.
    I know this is a consumer preview, but I repeat Microsoft is loosing again the chance to recover lot of pro audio users (Djs, producers etc etc) 
    I know high amount of Djs and producers/musicians....... who like windows but switch to mac time ago due the never ending and common DPC latency trouble.
    Is incredible Microsoft ignore this big market and continue ignoring
    millions of users around the world.
    Windows 8 is a great OS ultra faster, the best I tested from MS, but DPC latency issues make the OS non usable for PRO AUDIO ENVIROMENTS.





    • Edited by Groboto Sunday, April 8, 2012 11:29 PM
    Sunday, April 8, 2012 10:15 PM
  • also install the ADK / WPT and make a xperf trace.

    "A programmer is just a tool which converts caffeine into code"

    Sunday, April 8, 2012 11:37 PM
    Answerer
  • update the drivers and hope that it fixes the issue.

    "A programmer is just a tool which converts caffeine into code"

    Sunday, April 8, 2012 11:40 PM
    Answerer
  • update the drivers and hope that it fixes the issue.

    "A programmer is just a tool which converts caffeine into code"

    I think we've pretty well established that this has nothing to do with third party drivers.

    Sunday, April 8, 2012 11:52 PM
  • All drivers are up to date.
    LOL I supposed have to download and install tool of 2.3gb just for trace DPC latency, when latency mon tool do the same job and better?

    And why all that same machines under windows 7 not have any problem?
    Really is something on windows 8.......


    • Edited by Groboto Monday, April 9, 2012 7:14 AM
    Monday, April 9, 2012 6:26 AM
  • This tool make the same job, is free and very little:

    http://resplendence.com/latencymon

    All machines show same symptom.
    But all this machines work correctly with windows 7.

    Hoppe somebody from win8 team work in this ASAP.


    • Edited by Groboto Monday, April 9, 2012 6:48 AM
    Monday, April 9, 2012 6:44 AM
  • Like you can see is the same problem on machine of Andreasvb, but I see exact this same on 5 different machines!!
    if some windows 8 user want test, please download Latency Mon

    http://resplendence.com/latencymon 

    Run latencymon tool under widnows, 8, pres play button, the make click on DRIVERS.
    Wait just for 30 seconds for collect info, then capture your image and upload here for start make comparations.


    Monday, April 9, 2012 6:53 AM
  • If there's any comfort, you can run the web-download and choose custom and only install the Performance tools.

    I downloaded the new for Windows 8 and then it downloaded the correct Symbols and generated a readable dpc.txt.

    Something I noticed at beginning of a reboot was that if I didn't used µTorrent it didn't peaked, but still never goes under 1000 µs.

    Made a new trace, uptime about 3 days.

    http://snell.hest.nu/DPC_Interrupt.7z

    http://snell.hest.nu/dpc.txt

    Also made a little video demonstrating the issue, http://youtu.be/0Zh3b_vkfHw

    Edit: Fun thing is everything works after resuming from sleep, no peak at all for over 10 minutes now.




    • Edited by Andreasvb Monday, April 9, 2012 1:25 PM Resume from Sleep info
    Monday, April 9, 2012 12:54 PM
  • The trace shows again the same. TCPIP spikes. I think that the Network Location Awareness service is the cause which detects if you are connected to the internet:

    but the latency checker tool is wrong. You don't have 1000µs all the time. The highest values are 256µs-512µs (nVIDIA driver) and 1 large spike with the TCPIP. Ask Marvell for driver update to fix the TCPIP spikes.

    @falcon4

    I'll no longer reply to you. Your trolling sucks. I replied to Andreas, not to you.

    Too all others who think they have issues. DON'T use the LATENCY CHECKER ANY LONGER. THIS TOOL DISPLAYS WRONG DATA. IT IS SIMPLY TOO OLD. THE TOOL WAS MADE FOR XP. AND IF YOU HAVE ISSUE, START A NEW TOPIC AND PROVIDE THE XPERF TRACES, TO AVOID CONFUSIONS.


    "A programmer is just a tool which converts caffeine into code"

    Monday, April 9, 2012 6:07 PM
    Answerer
  • Thanks.

    I'll try disable the Network Location Awareness service and see if it's any better.

    Tried run VirtualBox and as soon I started a VM, DPC Latency Checker dropped to about 500 µs.

    But if I closed the program and started it again, while still running the VM the latency was back to 1000 µs.

    So I guess it's not so reliable like you wrote, too bad it's not working. Maybe someone else can make a new program for Windows 8 or they can update it.

    For the record, I've run all day without µTorrent and no spikes at all.

    Monday, April 9, 2012 8:57 PM
  • Andreasvb I think no is a network problem.

    http://resplendence.com/latencymon not show wrong information.

    Got to system and disable all network adapters and you see the trouble continue and not go better.

    I not pretend fight with Andre.Siegler, and say thanks for try help, anyway I follow what he said for see whats up.
    Please Andreasvb, disable all network related devcies just have to go to SYSTEM - HARDWARE DEVICES, disable lan and Wi-Fi and back here to confirm.

    I think what Andre.Siegler say is wrong, but we need fix this........... not fight.
    Andre.SIegler, please calmdown and don't goplease!,  falcon4, you too relax and stop fight and complaint about person try to help to others.

    We need really go more deep in this and the onlyway is test and test and test again.

    Falcon4, I think Andre.S is wrong, but not for that reason I attack to he.
    The way to arrive to conclusion for detect bug is testing, not fighting, falcon or you start please collaborate or stop please.




    • Edited by Groboto Tuesday, April 10, 2012 9:04 AM
    Tuesday, April 10, 2012 8:55 AM
  • I autoreply myself:
    http://www.microsoft.com/download/en/details.aspx?displaylang=en&id=28997

    For anyone want d a trace this is the download URL, download ADK, choose only install performance tools, is only 83.9mb no mor eike I say before.

    I back soon with some trace info.

    • Edited by Groboto Tuesday, April 10, 2012 9:01 AM
    Tuesday, April 10, 2012 8:59 AM
  • Ok here my trace

    What you think mr  Andre.Ziegler

    Based on this graphs, I not have big DPC latency trouble, but in the reality is the audio drop.
    The result is the same for multiple machines.
    Please send your opinion.







    • Edited by Groboto Tuesday, April 10, 2012 10:19 AM
    Tuesday, April 10, 2012 10:12 AM
  • I too am having the same problem. Installed Windows 8 64bit consumer preview this morning and have spent all day trying to sort this. My system is more than adequate. I checked all my drivers are updated, including the intel chipset one, turned off wireless and processor power management in the BIOS, and been through disabling various drivers, no change.

    Latency is on a constant level of ~1100 us, with no spikes - highest routine DPC execution time is 370 us from ndis.sys yet overall kernel timer latency is at that 1100 us level. Not wasting anymore time on this, going back with Win 7. Pity, I would have liked to beta test Win 8 with my music setup.

    Sunday, April 22, 2012 5:20 PM
  • I think this may be deliberate behavior in Win 8.  I read an MS blog that said they retuned the kernel to allow the cpu to sleep for longer intervals before waking up to do anything.  This is important for saving power on a mobile device, but it destroys performance for certain types of applications on a desktop or laptop.  I am rapidly reaching the conclusion that Win 8 will be a decent mobile OS, but a crappy desktop/laptop OS.  Too bad most of their installed base is the latter.

    Friday, April 27, 2012 2:04 AM
  • Hi,

    Just wanna bump up this thread cause i have the exact same "issue".

    With both DPC latency checker and LatencyMon

    Latency is on a constant level of ~1100 us, with no spikes - highest routine DPC execution time is 370 us from ndis.sys yet overall kernel timer latency is at that 1100 us level. Not wasting anymore time on this, going back with Win 7. Pity, I would have liked to beta test Win 8 with my music setup.

    Same thing here with highest routine DPC execution time on LatencyMon itself !



    • Edited by elTRex Saturday, May 19, 2012 6:59 AM
    Saturday, May 19, 2012 6:58 AM
  • What is your "real world" issue?  Just seeing a 1 millisecond latency in the DPC queue doesn't mean things are necessarily going to fail.

    Are you hearing stuttering audio, seeing dropped frames in video?

    I have been playing streaming audio from my Windows 8 system with 1+ ms latency without experiencing stuttering or dropouts.

     

    -Noel


    Detailed how-to in my eBook:  
    In development:

    Configure The Windows 7 "To Work" Options
    Configure The Windows 8 "To Work" Options

    Saturday, May 19, 2012 8:49 PM
  • Noel,

    I've been having audio stutter issues after installing Windows 8 x64 Consumer Preview, which brought me here.  I'm on a Dell Latitude D620 with an Intel Core 2 Duo T7200 2.0 GHz processor, 4 GB DDR2 RAM, Intel GMA 950, and a 500GB 7200rpm hard drive.

    Andre.Ziegler,

    I have the Windows Performance Toolkit installed, but for some reason, I'm get this message when trying to paste your command:

    'xperf' is not recognized as an internal or external command, operable program or batch file.
    As mentioned in the OP, Windows 8 isn't running with the same snappiness on my laptop as Windows 7 SP1 has.  Hope this issues gets resolved before long.  Thanks, guys!

    • Edited by BRDGTWN Monday, May 28, 2012 6:26 AM
    Monday, May 28, 2012 6:20 AM
  • Mine is running fine now with Windows 8 Release Preview!

    I did got it to sort of work in CP by turning off Network Location Awarness service.

    Maybe the Windows Audio Endpoint Builder one had something to do with it as well, though it requires some modification in registry to not be a dependency for Windows Audio.

    Saturday, June 9, 2012 5:18 PM
  • I don't find that stopping the Network Location Awareness service stops the DPC latency from being quite large - plus it came back on by itself after stopping it.

    I've never seen it go under 1 ms in Windows 8 RP, CP, or DP.

     

    -Noel


    Detailed how-to in my eBooks:  

    Configure The Windows 7 "To Work" Options
    Configure The Windows 8 "To Work" Options

    Saturday, June 9, 2012 8:53 PM
  • DPC Latency Checker is flawed,  doesn't work in Windows 8.

    If you start VirtualBox and a VM it will decrease visually, as I wrote earlier.

    I think you need to disable the service, not just stopping it, to prevent it start again.

    Worked great for me, didn't had to reboot, had about a month uptime.

    Sunday, June 10, 2012 9:13 AM
  • If this si true............wow, HOUSTON WE HAVE A PROBLEM:

    Microsoft has changed the way interrupts are
    handled by the hardware in Win8, supposedly to be more power-efficient. All
    interrupts are funneled to a single interrupt to the CPU.

    Edit: This just
    proves how MS doesn't care to make Windows 8 a "serious" OS - meaning, an OS for
    serious/professional users. They just want to make a pretty fisher-price block
    UI, dumbed-down for people to NEF on.

    SOURCE!

    http://forums.anandtech.com/showthread.php?t=2250925

    Monday, June 11, 2012 9:18 AM
  • Don't care where you see, this is on everywhere and users reporting this same trouble increase day by day:
    Example:

    https://forum.ableton.com/viewtopic.php?f=1&t=180259

    Monday, June 11, 2012 9:22 AM
  • I decided to try Release Preview fresh and used only xperf.  I performed three identical tasks on both Windows 7 and Windows 8 while recording an xperf trace in each task on the same machine.  Then compared them.

    The tasks were system idle, playing a MP3 locally and streaming a MP4 video off the wireless network.  I used the built-in default players in both operating systems (Windows Media Player/MetroZune) I did the trace for 2 minutes for each.

    The results were basically what everyone else has posted before, but here's the basic results:
    At Idle, top DPC latency:
     Windows 7, NDIS.SYS  Duration: 0.97ms 
     Windows 8, NDIS.SYS  Duration: 1.49ms

    Local MP3 playback, top DPC latency:
      Windows 7, NDIS.SYS Duration: 0.97ms
      Windows 8, NDIS.SYS Duration: 3.81ms

    MP4 streamed over network, top DPC latency:
      Windows 7, NDIS.SYS Duration: 0.98ms
      Windows 8, NDIS.SYS Duration: 14.32ms

    Also with the video I noticed some audio glitch at least once (which is what first alerted me to these problems many months ago).  Naturally the first thought would be to get rid of the NIC, but I did attempt to do that in the last release and other drivers started being a problem (storport.sys if I recall).  A few minutes trying to use the impaired pen input in Windows 8 on this X200 Tablet put me off any further testing.

    In the consumer preview the results were basically identical for me, where watching a DVD was not a smooth experience, nor was attempting to play fairly uncomplicated games or using software like Sibelius.  Where in Windows 7, on the same machine, using the same driver versions (of the third party variety anyway), all three perform without issue.


    Jonathan Kay

    Tuesday, June 12, 2012 5:28 AM
  • Awesome MS dont take care inmediatly about this..........
    Great for APPLE, in tis way djs from arround the world always continue using mac.......forever!
    And very important info, release preview have this problem, only the developer preview not have this problem on my machines.

    I try some sort of hack soon, for se eif can use some files form developer preview for fix this shit!



    • Edited by Groboto Friday, June 15, 2012 2:09 PM
    Friday, June 15, 2012 1:52 PM
  • I also get this issued, even in Windows 8 Release Preview. It can be temporarily fixed by restarting "Windows Audio" service, but the issue always returns.

    Saturday, June 23, 2012 4:47 AM
  • No fix available, MS aparently not intersted in fix this.............

    Tuesday, June 26, 2012 4:47 PM
  • Boys and girls, after search a lot across the web today I found a awesome free tool for improve DPC latency, work like  a charm on my HP Envy and other machines where I test this tool.  : )
    Finally my Win 8 DPC nightmare end!!

    http://www.smithsonmartin.com/free-tools/



    Im waiting for your votes : )
    • Edited by Groboto Tuesday, July 3, 2012 5:29 AM
    Tuesday, July 3, 2012 4:58 AM
  • Unbelievable, it works wonderful! Long expected. Thanks! Now overall latency level is green, only left some rare red pikes. 

    Tuesday, July 3, 2012 7:00 AM
  • Boys and girls, after search a lot across the web today I found a awesome free tool for improve DPC latency,

    I'm wary of new free tools that don't bother to describe what they actually do nor provide sources.  Are you certain this latency enhancer doesn't carry malware?  Have you gained any insight into how it works?

    -Noel


    Detailed how-to in my eBooks:  

    Configure The Windows 7 "To Work" Options
    Configure The Windows 8 "To Work" Options

    Tuesday, July 3, 2012 10:48 AM
  • I'd like to know too. DPC latency isn't something that can just be "tweaked", it's caused by low-level routines that take longer than they should to return control to the OS. That's bad programming, and it's like placing a band-aid on an engine and hoping it'll give you better mileage. Site is full of "results" and "testing" but does little to explain what it actually tries to do...

    Sounds to me like a program designed to just hack test results of DPC latency tools. There was a suite of programs some years ago, things like AntiCrash, Battery enhancer, memory booster, etc., all by one company... turns out none of the programs did _anything_ except take up space and look pretty (before these programs were really "malware"). Ever since then, I'd been hesitant to try programs with outlandish claims like this...

    Tuesday, July 3, 2012 11:09 AM
  • I just tested it in an isolated virtual machine, which I subsequently reverted after testing.  The system didn't like opening the executable ("it may harm your computer!"), but that's just because it's very new.

    The application runs minimized to the system tray once you hit the [Hide] button.  Task Manager reveals it to be running at Real Time priority.

    Sure enough, it pushes the DPC Latency down some, under 1 ms most of the time, as shown in the readout from the DPC Latency Checker (it goes from consistently yellow to mostly green).  When it is stopped the latency goes back up.

    As a test, just to see if it is just tweaking some registry value or something, then "un-tweaking" it on graceful exit, I killed the process with Task Manager.  The latency reverted back up to between 1 and 2 ms after it was gone.

    I don't know what a program could be doing to work like this.  As you've said, Falcon4, that's not typically how performance tweaking is accomplished.  Running more software does not normally a more efficient system make!

     

    -Noel


    Detailed how-to in my eBooks:  

    Configure The Windows 7 "To Work" Options
    Configure The Windows 8 "To Work" Options

    Tuesday, July 3, 2012 11:42 AM
  • I've just upgraded from Windows 7 Ultimate to Windows 8 Release Preview.. I noticed that DirectX graphics performance has been reduced not only in average frame rate, but there are spikes of delay too.

    I checked the DPC Monitor and found it almost rock solid at 1000us like you guys have been reporting.

    Drivers have all been updated.

    So far Windows 8 can't be used a gaming platform.

    Wednesday, July 4, 2012 12:39 PM
  • I noticed a new message on the DPC Latency Checker web site that indicates all prior results from the DPC Latency Checker are probably flawed...

     

    From:  http://www.thesycon.de/eng/latency_check.shtml

    Windows 8 Compatibility: The DPC latency utility runs on Windows 8 but does not show correct values. The output suggests that the Windows 8 kernel performs badly and introduces a constant latency of one millisecond which is not the case in practice. DPCs in the Windows 8 kernel behave identical to Windows 7. The utility produces incorrect results because the implementation of kernel timers has changed in Windows 8 which causes a side effect with the measuring algorithm used by the utility.  Thesycon is working on a new version of the DPC latency utility and will make it available on this site as soon as it is finished.

     

    -Noel


    Detailed how-to in my eBooks:  

    Configure The Windows 7 "To Work" Options
    Configure The Windows 8 "To Work" Options


    Saturday, August 25, 2012 9:44 PM
  • that's what I told you, but falcon4 only trolled around instead of understanding this.

    Use LatancyMon or xperf to debug it.


    "A programmer is just a tool which converts caffeine into code"

    Tuesday, August 28, 2012 12:36 PM
    Answerer
  • Windows 8 RTM here, all latest (Intel) chipset drivers installed, TI-based expresscard firewire on an HP Pavilion dv6t.
    In Windows 7 SP1, my TC Electronic desktop konnekt6 worked like a charm. No drop outs, no desyncing, no nothing. In Windows 8, however, when I listen to music for an extended period of time, the music becomes garbled at a point. The problem does not go away unless I re-initialize the audio interface to another sampling rate. Using the DPC checker tool provided by TC, I discovered much more latency than before (used to get 400us max, now it's always more than 1000us), and have to run the interface in safe mode (just a driver setting). Since I see many people online have double the DPC latency they had with Windows 7, I don't think it's a driver issue. So what now? I just wanted to mention my case, to confirm everyone's findings here. One thing that did get fixed though: device now hot swaps correctly, it re-initializes 100% of the times I unplug and plug it back in, resuming any playback in progress.
    Saturday, September 8, 2012 9:54 PM
  • There's nothing about that change in readouts from the DPC Latency Checker that has anything to do with your problem.

    Read a couple of posts up and follow that link.

    I suspect the drivers just aren't all mature for Windows 8.

     

    -Noel


    Detailed how-to in my eBooks:  

    Configure The Windows 7 "To Work" Options
    Configure The Windows 8 "To Work" Options

    Sunday, September 9, 2012 12:43 AM
  • as I told the other users, install the WPT and make a xperf trace.

    "A programmer is just a tool which converts caffeine into code"

    Sunday, September 9, 2012 7:01 PM
    Answerer
  • Hello!

    So far I read a lot of unneccessary posts regarding how to use some kind of software. What is frustrating to me is not to find a solution for my Dell XPS 17.

    What I find on the net so far:

    • Update drivers and Bios and all will work fine which afaik doesn't!
    • There is one group crucifying Microsoft for buggy DPC in some certain combinations of hardware.
    • The next group wants to crucify Intel for bad programming of drivers.
    • I myself crucify Dell for bad Bios progamming because their auto configured interrupt sharing uses one IRQ for PCI-Express Controller, TV-Card, USB-Controller, PCI-Express Root Port 1 (Avermedia), PCI-Express Root Port 5 (n.a.), Intel Management Engine Interface and Geforce GT555M. All other cards share an interrupt for maximum with 2 hardware items. This opens a bottle neck and from the past we all knew not to share interrupts with too much hardware items.
    • And not to forget the groups telling how to use DPC Latency Checker, Latency Mon or WPT which all do the same.

    This softwares to check DPC are a nice to have to check where the problems remain, fastest software is Latency mon.

    But they will not help you to find a solution on what to do. So what solutions can be given for Dell XPS17?

    Regards

    Filiaap

    P.S.: In some cases it may help to deactivated Powermizer of NVidia Card causing such laggs.


    • Edited by Filiaap Tuesday, September 11, 2012 9:35 PM
    Tuesday, September 11, 2012 9:06 PM
  • Hey Filiaap,

    I wouldn't say the software is completely unnecessary, if you were using Windows 7 or had a new machine made in the next six months, it would be totally valid and useful to deal with a possible bad driver.  However in the scenario of the older hardware and Windows 8 RTM (or before, using the beta/previews), it isn't.

    There's also more than one issue being expressed here.  On Windows 8, you see at least 1000us DPC timings because of how Microsoft has tweaked the system - this supposedly shouldn't cause any impact on visible performance (so we've been told anyway).  But on some hardware (for example, my thinkpad), it goes beyond 1000us into the ~30ms range and fairly simple operations like playing a MP3 or watching a DVD become painful and unpractical.

    Regardless of what camp you're "crucifying" (good usage of the word!), the likelihood of seeing a fix from any of these companies is practically zero now unless your hardware is brand new.  This is why a lot of us were vocal here and elsewhere during the development process of Windows 8 because that was the only window of opportunity for this to be fixed.  That window is now closed.

    Of course there's always a chance some of these issues will be dealt with but I'm not holding my breath.  Personally, I am refusing to use Windows 8 for this and many other issues which makes the operating system useless to me. 

    Thus the only real solution here so far is to use Windows 7 and almost all the "enhancements" to the desktop side of Windows 8 can be achieved in other ways on 7 anyway.


    Jonathan Kay

    Wednesday, September 12, 2012 2:37 PM
  • there's always a chance some of these issues will be dealt with

    Kind of depends...  Say you're a hardware company - for the sake of argument say you're a graphics card maker.  You'd like to be known as the one that doesn't leave your existing customers high and dry, so you budget some money to create Windows 8 drivers so that people using your existing products won't have a bad experience when they upgrade to Windows 8.

    Since Windows 8 isn't fundamentally different than Windows 7 deep down, that might not even be too terribly hard to do.  It might just be a matter of making your installer aware of Windows 8, and maybe tweaking a few version checks here and there.

    In fact, ATI Catalyst drivers are already available for Windows 8 (Catalyst 12.8, coincidentally).

    On the other hand, it could be that a hardware company who cares less about their customers might just choose NOT to upgrade older drivers, which may not work at all, or just not very well.  It could be that the changed rules for using the high speed timer could end up being a sticky wicket, and it would cost something to update the drivers for all the old products.  Or it could be that the managers of said company might feel that the Windows 8 release is just an opportunity for them to sell more of their new hardware.  So the old stuff doesn't work very well, and after a time people will spread the word that the newest hardware, with the "designed for Windows 8" moniker on it, works fine.

    It's always been like this.  I don't know how many flatbed scanners I've thrown away because the drivers for those things were virtually NEVER updated for new OSs.

    With a new OS release, if we want the gadgetry to all work we're at the mercy of what the manufacturers decide to do.  One could be forgiven for wanting to hold off upgrading to Windows 8 (if "up" is the right term there) until these issues are better known.

     

    -Noel


    Detailed how-to in my eBooks:  

    Configure The Windows 7 "To Work" Options
    Configure The Windows 8 "To Work" Options

    Wednesday, September 12, 2012 7:27 PM
  • Mind taking a look at mine?

    dpc.txt: http://www.datafilehost.com/download-246f837d.html

    DPC_Interrupt.etl: http://www.datafilehost.com/download-4c56bb18.html

    Wednesday, September 19, 2012 2:30 AM
  • that's what I told you, but falcon4 only trolled around instead of understanding this.

    Use LatancyMon or xperf to debug it.


    "A programmer is just a tool which converts caffeine into code"

    would you mind having a look at mine? I am a dj and i had my latency problem in windows 7 fixed but now i run into new latency problems with windows 8.

    i am aware of DPC checker not displaying accurate results, but i have experienced distortion, popping, drop outs and over all freezing from my system while playing music.

    Tuesday, November 6, 2012 7:46 AM
  • i am aware of DPC checker not displaying accurate results, but i have experienced distortion, popping, drop outs and over all freezing from my system while playing music.

    run the xperf commands, zip the file, upload it and create a new topic in the Win8 Performance forum:

    http://social.technet.microsoft.com/Forums/en-US/w8itproperf/threads


    "A programmer is just a tool which converts caffeine into code"

    Tuesday, November 6, 2012 2:04 PM
    Answerer
  • i am aware of DPC checker not displaying accurate results, but i have experienced distortion, popping, drop outs and over all freezing from my system while playing music.

    run the xperf commands, zip the file, upload it and create a new topic in the Win8 Performance forum:

    http://social.technet.microsoft.com/Forums/en-US/w8itproperf/threads


    "A programmer is just a tool which converts caffeine into code"

    hey thanks for the quick response. I have started a new topic here

    http://social.technet.microsoft.com/Forums/en-US/w8itproperf/thread/8a8a1af6-847a-499d-b9b2-25e29198f206

    Wednesday, November 7, 2012 12:14 AM
  • I have been having the exact same problem and have been pulling my hair out trying to resolve it... done it all: Update BIOS, drivers, ran wired internet and disabled wireless, methodically disabled everything one at a time... still having major issues playing video.

    I apologize for not being extremely tech savvy, but this is my info:

    Windows 8 Pro 32 bit

    Intel Core Duo @ 2GB X2

    3GB ram

    Direct X 11

    I ran DPC Latency Checker and ndis.sys shows as a problem.  However when I run wired internet, I still have issues. This computer was awesome on Vista (as awesome as a comp can be on Vista, that is)

    Wednesday, November 7, 2012 3:40 AM
  • Issue is still in final :(
    Saturday, February 16, 2013 10:18 PM
  • There may not be an "issue in final" in the sense you mean, Kamakzie.  Many people run Windows 8 without latency issues.  Perhaps you could describe what's happening to you more specifically?

    Chances are the Windows 8 drivers for your particular hardware aren't yet mature, that's all.  If you ask nicely Andre Ziegler might even analyze your xperf traces if you take the time to do them.

    And jet228, it's been stated up above that DPC Latency Checker doesn't work with Windows 8.  Look right on their page:  "The DPC latency utility runs on Windows 8 but does not show correct values."

     

    -Noel


    Detailed how-to in my eBooks:  

    Configure The Windows 7 "To Work" Options
    Configure The Windows 8 "To Work" Options

    Sunday, February 17, 2013 1:26 AM
  • Interesting. That message about Windows 8 compatibility is definitely new. I didn't believe there could be such a significant change that it would cause a very trusted and reliable tool, the DPC Latency Checker, to actually be incorrect on Windows 8 alone - didn't think Windows 8 would have so many changes it would cause such a thing. Shame it's still a terrible OS that turns a computer into a big-screen smartphone ;) (sorry, had to say it)

    But yeah, now that the author of the DPC tool actually noted the problem on the site, I guess we can drop this... in my mind I still trusted the DPC Latency Checker and thought Win8 was just screwy with the network DPCs. Guess it's not so bad after all...

    Sunday, February 17, 2013 4:12 AM
  • Boys and girls, after search a lot across the web today I found a awesome free tool for improve DPC latency, work like  a charm on my HP Envy and other machines where I test this tool.  : )
    Finally my Win 8 DPC nightmare end!!

    http://www.smithsonmartin.com/free-tools/



    Im waiting for your votes : )

    Just tried this and I still get sound stuttering.  I've been conversing with Andre in another thread and we can't seem to get this figured out.  My trace shows ndis.sys causing most of my issues and I've tried 3 different NIC's with the latest being a Intel CT NIC which should be the best and it still gives me a bunch of DPC errors which intern give me audio glitches.  I really don't want to take the time to reinstall Windows 7 but I might have to try as this is driving me nuts!

    • Edited by Kamakzie Friday, March 1, 2013 4:07 AM
    Friday, March 1, 2013 1:34 AM
  • Well I bit the bullet and installed Windows 7 Ultimate 64 again and its great in comparison to 8.  Must be drivers that aren't compatible or something.  I have 8 still on another hard drive.
    Friday, March 1, 2013 10:47 PM
  • A reasonable thing to do, and what do you lose?  Nothing worth having.

    Will staying back on Windows 7 be viable forever?  Certainly not, but maybe long enough until Microsoft (or someone else) releases a good alternative.

     

    -Noel


    Detailed how-to in my eBooks:  

    Configure The Windows 7 "To Work" Options
    Configure The Windows 8 "To Work" Options

    Saturday, March 2, 2013 4:01 AM
  • Well well well.  I think I finally found the issue.  It was Malwarebytes anti malware program causing the issue.  I exit the program and everything is fine.  I apologize to the Windows 8 developers for complaining.  I hope me posting this helps another poor unfortunate soul! :P  Looks like you can still use Malwarebytes but disable Malicious website blocking.  Otherwise it fubars ndis.sys

    • Edited by Kamakzie Saturday, March 2, 2013 5:52 AM
    Saturday, March 2, 2013 5:50 AM
  • Andre.Ziegler pontificated:

    as I told the other users, install the WPT and make a xperf trace.


    "A programmer is just a tool which converts caffeine into code"


    There seems to be an echo in here.
    Wednesday, March 6, 2013 7:46 AM
  • Kamakzie saved the world:

    Well well well.  I think I finally found the issue.  It was Malwarebytes anti malware program causing the issue.  I exit the program and everything is fine.  I apologize to the Windows 8 developers for complaining.  I hope me posting this helps another poor unfortunate soul! :P  Looks like you can still use Malwarebytes but disable Malicious website blocking.  Otherwise it fubars ndis.sys

    OMG!  So easy.  An infinitude of gratitude, Kamikaze.  This has been driving me nuts on Windows 7 since about mid January when Oracle nearly destroyed my system with it's browser Java open door.  (EVERYONE TURN OFF JAVA IN BROWSERS IN SECURITY IN JAVA CONTROL PANEL).   Of course that's exactly when I installed Malware Bytes.  I suspected the infection Oracle slipped to me as the cause of this but never something I installed to fend off its destructive powers.

    DPC Latency Checker (which does work fine on 7) went from about a 20% chance of a red spike in any interval with clusters of many red intervals to just plain ol' green.  ndis.sys never over 150 usec instead of 27,000.  I wish I could get paid my old rates for the amount of time I've spent on this problem without denting it.   That would be about a year's current income.  :-)

    How on earth did you find it?  I'm in glitch free heaven!

    Andre.Ziegler,

    How come your vaunted and too often repeated ADK/xperf magic wand didn't pick this one right off?

    Wednesday, March 6, 2013 9:03 AM
  • Kamakzie saved the world:

    Well well well.  I think I finally found the issue.  It was Malwarebytes anti malware program causing the issue.  I exit the program and everything is fine.  I apologize to the Windows 8 developers for complaining.  I hope me posting this helps another poor unfortunate soul! :P  Looks like you can still use Malwarebytes but disable Malicious website blocking.  Otherwise it fubars ndis.sys

    OMG!  So easy.  An infinitude of gratitude, Kamikaze.  This has been driving me nuts on Windows 7 since about mid January when Oracle nearly destroyed my system with it's browser Java open door.  (EVERYONE TURN OFF JAVA IN BROWSERS IN SECURITY IN JAVA CONTROL PANEL).   Of course that's exactly when I installed Malware Bytes.  I suspected the infection Oracle slipped to me as the cause of this but never something I installed to fend off its destructive powers.

    DPC Latency Checker (which does work fine on 7) went from about a 20% chance of a red spike in any interval with clusters of many red intervals to just plain ol' green.  ndis.sys never over 150 usec instead of 27,000.  I wish I could get paid my old rates for the amount of time I've spent on this problem without denting it.   That would be about a year's current income.  :-)

    How on earth did you find it?  I'm in glitch free heaven!

    Andre.Ziegler,

    How come your vaunted and too often repeated ADK/xperf magic wand didn't pick this one right off?


    It was kind of by chance that I found it.  I got so sick of windows 8 because of the issue that I reinstalled windows 7.  As I was reinstalling programs I had DPCLat.exe running and when installed Malwarebytes my DPC stats went from green to red garbage numbers.  I uninstalled Malwarebytes and everything was fine again.  You can actually run Malwarebytes just make sure to click the protection tab and uncheck the enable Malicious Website blocking.  That is the one that just hammers ndis.sys.
    Wednesday, March 6, 2013 6:00 PM

  • It was kind of by chance that I found it.  I got so sick of windows 8 because of the issue that I reinstalled windows 7.  As I was reinstalling programs I had DPCLat.exe running and when installed Malwarebytes my DPC stats went from green to red garbage numbers.  I uninstalled Malwarebytes and everything was fine again.  You can actually run Malwarebytes just make sure to click the protection tab and uncheck the enable Malicious Website blocking.  That is the one that just hammers ndis.sys.

    Doncha just love blind luck?  :-)   Thanks so much for coming here to share it. 

    Productive again at last.  I was about to dump the system to a migration file, fresh install Win 7 and migrate back.  Probably ought to do that anyway after a major infection.

    Thursday, March 7, 2013 2:55 AM