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NetworkThrottlingIndex - Does not fix poor network performance

    Question

  • Well I was excited to here we could change the network throttling index value (NetworkThrottlingIndex) in SP1 but it does not seem to work well.  I changed it from the default (10) to 0 and to 100 and rebooted for both tests.

     

    NetworkThrottlingIndex = 0 (3.9% Network Utilization while playing music)

    NetworkThrottlingIndex = 100 (13% Network Utilization while playing music)

     

    With Mediaplayer even open it is still slow and the same goes for IE depending on the page I had accessed.  If I close Mediaplayer (IE closed too) my network utilization jumps up to about 30-40% on a GB network.

     

    Here is the comment I noticed in the notable changes.

     

    "In SP1, PC administrators are able to modify the network throttling index value for the MMCSS (Multimedia Class Scheduling Service), allowing them to determine the appropriate balance between network performance and audio/video playback quality."

     

     

    Microsoft please fix this and document the settings for NetworkThrottlingIndex.  With today's Dual/Quad core systems it should be a non-issue.  In XP everything worked great now with MMCSS in Vista it reminds me of the days of burning a CD and not touching the mouse because I might get a toaster.  Now with Vista on my fast PC I can't copy files fast unless I leave my PC alone (Can't even browse the internet).

     

    Thanks,

     

    Kent

    Tuesday, December 11, 2007 7:40 AM

Answers

  • Without any audio application I have network throughput of 96% translating to 110 MiB/second traffic to and from my linux samba server. I use 2500 (larger sizes was actually slower) bytes ethernet frame size for my gigabit network.

    Setting NetworkThrottlingIndex to higher values results in traffic beeing throttled to 50% of gigabit speed.

    I found that setting NetworkThrottlingIndex to 0xffffffff will actually turn off throttling altogether. This allows me to reach full 96% gigabit utilization at the same time as using multimedia applications.

    It seems that the upper cap on throttling is turned down to low, you might want to turn it to 75% of full speed for example, and I'm guessing that this gets even worse for 1500 packet size, theoretically only beeing able to reach 30% of gigabit speed.

    Saturday, December 15, 2007 9:38 AM

All replies

  • Hi, Kent. Sorry for the delayed response. I'm a tester at MS working to reproduce the problem you mentioned and I'd appreciate it if I could get some more info from you.

     

    Could you tell me what kind of machine you're running this on? I'd especially like to know things like the processor, amount of RAM you have, and the manufacturer of the network card you're using. If you're not sure how to get this information let me know and I'll get you some detailed instructions.

     

    Also, I'm assuming that you're testing this by copying a file to whatever machine is playing music and watching results in Task Manager. Can you tell me what media player you're using and exactly what kind of traffic you're generating?

     

    And just for reference, a NetworkThrottlingIndex of 0 ends up being translated to a value of 1, which is still an extremely throttled setup. Larger indexes should translate to better bandwidth.

     

    Thanks for your help, Kent.

     

     

     

    ablawas [MS]

     

     

     

    Saturday, December 15, 2007 1:52 AM
  • Sure here is the info

     

    Vista SP1 RC1 32Bit

    Dell Precision 390

    Intel Core 2 Extreme X6800 @ 2.93Ghz

    4GB RAM (3.4 available)

    Broadcom NetXtreme 57xx Gigabit Controller (Driver version is 10.10.0.1)

     

    Target System #1

    Windows Server 2003 R2 w/SP2, 64Bit

    Intel Core 2 Quad Q6700 @ 3.2Ghz

    Gigabyte P35-DS3R

    8GB RAM

    Realtek RTL8168/8111 PCI-E Gigabit Ethernet NIC

     

     

    Target System #2 (Media Center PC)

    Windows Vista SP1 RC1 32Bit

    Intel Core 2 Due E6600 @ 2.5Ghz

    Gigabyte 965P-DS3 Motherboard

    2GB RAM

    Marvell Yukon 88E8053 PCI-E Gigabit Ethernet Controller

     

     

    Windows Media Player is the media player I use

    In Internet Explorer with a Flash Movie (Flash Version 9.x)

    File types can vary but I have tested recently with .mpg, .img and .iso.  Up to 5GB in size for the files.

     

     

    OK here is what I know (NetworkThrottlingIndex = 100)

    Copying a file to Windows Server 2003 R2 64Bit slows down when Windows Media Player is running.

    Copying a file to Windows Server 2003 R2 64Bit slows down when Internet Exporer is open and I have played a Flash Movie (www.harrypotterorderofthephoenix.com/)

     

    Copying a file to Windows Vista RC1 32Bit (Media Center PC) is fine.

     

    I have not tested this yet but in the past if I had Media Center open it would cause the same problem when copying a file to it from my Dell P390.

     

    Hope that helps.  Let me know if you need more info or more technical details.

     

    Kent

     

    Saturday, December 15, 2007 3:29 AM
  • Without any audio application I have network throughput of 96% translating to 110 MiB/second traffic to and from my linux samba server. I use 2500 (larger sizes was actually slower) bytes ethernet frame size for my gigabit network.

    Setting NetworkThrottlingIndex to higher values results in traffic beeing throttled to 50% of gigabit speed.

    I found that setting NetworkThrottlingIndex to 0xffffffff will actually turn off throttling altogether. This allows me to reach full 96% gigabit utilization at the same time as using multimedia applications.

    It seems that the upper cap on throttling is turned down to low, you might want to turn it to 75% of full speed for example, and I'm guessing that this gets even worse for 1500 packet size, theoretically only beeing able to reach 30% of gigabit speed.

    Saturday, December 15, 2007 9:38 AM
  •  

    Hello Erik, I tried setting NetworkThrottlingIndex to 0xffffffff and yes it does seem to turn off throttling altogether.  Good catch and thanks.

     

    At this time I have not changed my frame size from the defaults as I thought it could cause some issues.  I might give that I try to get the max speed out of my Gigabit network after doing a little more research into the pros/cons.

     

    Kent

    Saturday, December 15, 2007 6:36 PM
  • Hi, Kent. Keep in mind that the NetworkThrottlingIndex registry key is only intended to alter received network traffic, as opposed to sent network traffic. Playing a media app in Vista does two primary things regarding performance:

     

    1. The media app is given a high priority when scheduling time on the CPU.

    2. The network stack slows down the rate of received traffic

     

    I suspect that the first phenomenon is what slows down your file copies from Vista SP1 to Server 2003. Since NetworkThrottlingIndex was designed to address the second phenomenon, you didn't see any difference in throughput.

     

     

    But there is a way to alter the behavior of the scheduler so that all OS operations are more responsive. You should have noticed a registry key called SystemResponsiveness at the same location as NetworkThrottlingIndex. SystemResponsiveness defines the maximum percentage of CPU time that will NOT be used by the multimedia scheduler for media apps, with a default of 20%. As you turn that value up and reboot, you should notice that OS operations will be affected less and less by playing media. As a consequence, you might experience worse media playback, with the occasional jittery or glitchy output.

     

    With that in mind, feel free to try out some different values for these registry keys and let me know if you see better network performance in both the send and receive situations. Any NetworkThrottlingIndex value above 100 ought to cause no throttling to occur, which means playing media should have no effect on received network throughput. Again, just be aware that media performace might suffer to compensate.

     

    Thanks,

     

    ablawas [MS]

     

     

    Thursday, December 20, 2007 12:49 AM
  • Hi,

    I have a very similar problem and it has been going on for a while now. I was hoping Vista SP1 would fix it, but it seems it hasn't.

    My problem is that audio becomes unplayable (lots of jittery and glitchy output) and the responsiveness of the system as a whole is impacted (like moving the mouse is no longer smooth, windows open/close with a delay,...) when my upload speed riches 150 KB/sec or more.

    I'm using uTorrent (1.7.7) to download torrents and Winamp (5.52) to listen to audio. As soon as my uTorrent upload riches 150 KB/sec the music starts to jitter and crackle. As the upload speed increases (I've got a 20 Mbit down and 4 Mbit up VDSL line) the music and the system becomes almost unusable.

    I've tried changing both the NetworkThrottlingIndex and SystemResponsiveness registry keys to max values (0 and 100) and restarted the system. It didn't seem to have any impact on this problem at all.

    I also tried disabling the Receive Window Auto-Tuning (netsh interface tcp set global autotuninglevel=disabled) hoping it would help, but it didn't.

    It seems there is a connection between the number of internet connections, the upload/download network utilization and audio/video playback on Vista (had zero problems on XP).

    Any help on how to fix this would be very, very welcome.

    Regards,
    Tr0n
    Wednesday, February 20, 2008 3:08 PM
  • I forgot to add my system info.

        Computer:
    Computer Type ACPI x86-based PC
    Operating System Microsoft Windows Vista Ultimate
    OS Service Pack Service Pack 1
    Internet Explorer 7.0.6001.18000
    DirectX DirectX 10.0

    Motherboard:
    CPU Type DualCore Intel Core 2 Duo E6300, 3000 MHz (7 x 429)
    Motherboard Name Asus P5B Deluxe (3 PCI, 1 PCI-E x1, 2 PCI-E x16, 4 DDR2 DIMM, Audio, Dual Gigabit LAN, IEEE-1394)
    Motherboard Chipset Intel Broadwater P965
    System Memory 2048 MB (DDR2-800 DDR2 SDRAM)
    BIOS Type AMI (01/22/07)
    Communication Port Communications Port (COM1)

    Display:
    Video Adapter NVIDIA GeForce 8800 GT (512 MB)
    Video Adapter NVIDIA GeForce 8800 GT (512 MB)
    3D Accelerator nVIDIA GeForce 8800 GT
    Monitor Generic PnP Monitor [NoDB] (170116843009)
    Monitor Samsung SyncMaster 930B (Digital) [19" LCD] (HMEY801108)

    Multimedia:
    Audio Adapter Analog Devices AD1988B @ Intel 82801HB ICH8 - High Definition Audio Controller [B-0]

    Storage:
    IDE Controller Intel(R) ICH8 2 port Serial ATA Storage Controller - 2825
    IDE Controller Intel(R) ICH8 4 port Serial ATA Storage Controller - 2820
    IDE Controller Standard Dual Channel PCI IDE Controller
    Storage Controller Microsoft iSCSI Initiator
    Storage Controller SCSI/RAID Host Controller
    Disk Drive WDC WD1200BB-00DAA1 ATA Device (111 GB, IDE)
    Disk Drive WDC WD2500JD-00HBC0 ATA Device (232 GB, IDE)
    Optical Drive TEAC DV-W50D ATA Device (DVD+RW:4x/2.4x, DVD-RW:4x/2x, DVD-ROM:12x, CD:16x/10x/32x DVD+RW/DVD-RW)
    Optical Drive XQ4127Q RWI815L SCSI CdRom Device
    SMART Hard Disks Status OK

    Network:
    Network Adapter Marvell Yukon 88E8001/8003/8010 PCI Gigabit Ethernet Controller


    Wednesday, February 20, 2008 3:15 PM
  • No ideas? Indifferent
    Friday, February 22, 2008 5:57 AM
  • Hi, Tr0nc3k. Sorry for the late response. I've got a couple of possible explanations and I'd like some more info from you to figure out what's going on.

     

    The two registry keys you altered are only expected to affect received network traffic, which doesn't seem to be what's causing the problem with your audio playback. Instead, it sounds like sending traffic to others is what causes this slow behavior. So at the moment I think the problem lies somewhere else.

     

    One possible cause is some adverse interaction between uTorrent and some other app. The uTorrent forums suggest that when uTorrent is running, Kereo and Sunbelt Personal Firewalls and Avast! P2P shield can force the CPU to run at 100%, which could cause the audio problems you heard. Did the CPU utilization hit 100% on your machine when your uTorrent uploads reach 150KB? If so, you might want to experiment with temporarily disabling or replacing any AV or firewall applications you might have installed.

     

    Another possibility is that Winamp and uTorrent are simultaneously trying to communicate with a hard disk drive and as the number of uTorrent uploads increases, the disk drive has a harder and harder time keeping up. Do you have both apps reading media off of the same hard drive? If so, do you have audio problems when you play music in Winamp off of a CD or a USB drive?

     

    Let me know if any of these ideas helps you out. If they don't, I'll keep investigating to see what the problem could be.

     

     

    ablawas [ms]

    Tuesday, February 26, 2008 12:48 AM
  • Hi ablawas and thanks for the response. Smile

    "
    Instead, it sounds like sending traffic to others is what causes this slow behavior."

    Yes, this only happens with outgoing traffic.

    "
    Did the CPU utilization hit 100% on your machine when your uTorrent uploads reach 150KB?"

    It didn't hit 100% but CPU usage did begin to spike when I removed the upload limit and let uTorrent upload beyond 150 KB/sec while audio or video was playing and started to cracle. I've uploaded a screenshot of the CPU usage history.

    http://freeweb.t-2.net/tron/memory.jpg

    The first spike is when Winamp was playing audio and I increased uTorrents upload speed and the second one was when I watched a mms stream (mms://...) over Windows Media Player and also increased uTorrents upload speed (Winamp was closed down).

    I'm using AVG and the integrated Windows Firewall.

    The interesting thing is that if I for example upload a file via FTP with max upload speed (500 KB/sec) I don't get any audio/video hickups, but if I use uTorrent I do.

    It might be a uTorrent problem or a problem when too many active connections are open.

    "
    Do you have both apps reading media off of the same hard drive?"

    No, the media is on a different hard drive. It also happens when I watch movies for example or in general when there is audio playing.
    Wednesday, February 27, 2008 9:41 PM
  • Ok, never mind.

    The sound/media problems also happen with FTP uploads, not just uTorrent. Just tested with FlashFXP and uploaded a lot of small files and the audio started to jitter.

    So it's not just isolated to uTorrent but a global Vista outgoing traffic problem.
    Sunday, March 02, 2008 9:56 PM
  • So yeah, still having this problem. Even got a faster HD (Raptor) to see if it would fix it, but it didn't.

    ;(
    Saturday, April 05, 2008 9:29 AM