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64 bit Windows 7 memory usage RRS feed

  • Question

  • I have juust noticed that although I have loaded the 64bit version the System Information screen states Installed Memory 4GB (usable 3.25GB). Why? I know the 32bit can only use 3.2G5B, but surely the 64bit can use up to 1TB!
    Friday, June 19, 2009 9:55 PM

Answers

  • install more than 4GB. 

    The reason why you are missing .75GB is because the nature of x86 hardware.  Well your video card is the most since you may have 256MB video memory, plus PCI buss requires 512MB memory or so of reserved system memory.

    This is the x86 memory hole.  This is a hole in virtual memory.  32-bit can access 4GB but because of this memory hole it only uses 3.25GB.  This hole still exists in x64 just for people with 4GB. 

    Installing more Ram than 4 GB should fix it.
    • Marked as answer by SaMcp1123 Saturday, June 20, 2009 3:11 AM
    Friday, June 19, 2009 11:06 PM

All replies

  • install more than 4GB. 

    The reason why you are missing .75GB is because the nature of x86 hardware.  Well your video card is the most since you may have 256MB video memory, plus PCI buss requires 512MB memory or so of reserved system memory.

    This is the x86 memory hole.  This is a hole in virtual memory.  32-bit can access 4GB but because of this memory hole it only uses 3.25GB.  This hole still exists in x64 just for people with 4GB. 

    Installing more Ram than 4 GB should fix it.
    • Marked as answer by SaMcp1123 Saturday, June 20, 2009 3:11 AM
    Friday, June 19, 2009 11:06 PM
  • Hi, I am having the exact same issue. However I have 6GB installed memory as reported in system properties. 6GB installed (3.25GB usable). My motherboard (ASUS M1500 - BIOS R01-A1) supports up to 8GB and reports 6144 in bios.

    I had a major headache even getting Windows to boot with more than 3GB finally resorting to MSCONFIG > BOOT > ADVANCED and specifying the max memory. Otherwise I get a blue screen that reports a problem with atikmdag.sys, booting from onboard graphics gets around this but the memory limit (3.25GB) still remains. I've tried enabling and disabling memory hole remapping to no avail. I'm full out of ideas, any suggestions would be appreciated.
    Friday, July 3, 2009 7:07 AM
  • I'm having the same problem. I have 6 GB of ram installed, BIOS reports it correctly, even windows reports it correctly, however it says it only has 3.25 GB of ram usable.

    Anyone found a solution to this problem? This was the whole reason I upgraded to a 64 bit OS.
    • Proposed as answer by CopierGuy Friday, September 4, 2009 1:32 AM
    Saturday, July 18, 2009 2:02 AM
  • I have juust noticed that although I have loaded the 64bit version the System Information screen states Installed Memory 4GB (usable 3.25GB). Why? I know the 32bit can only use 3.2G5B, but surely the 64bit can use up to 1TB!

    I'm having the same problem. I have 6 GB of ram installed, BIOS reports it correctly, even windows reports it correctly, however it says it only has 3.25 GB of ram usable.

    Anyone found a solution to this problem? This was the whole reason I upgraded to a 64 bit OS.
    It could also be faulty ram, have you tried to run a ram diagnostic tool to see if your ram may not be functioning properly?

    Experience is Use/Knowledge and understanding that Use/Knowledge is the key to Experience. -JJTech

    Windows 7 RC: Remember now this OS is not final and is Subject to all kinds of things that can very on different hardware. -JJTech
    Saturday, July 18, 2009 2:06 AM
  • Ok, my problem was that I had an old BIOS and there was no update. I just installed a new mainboard and using all the same components, 7  runs great!!! The board should have supported up to 8GB, but in practice it did not seem to be the case. I don't know the exact reason, memory timings perhaps? I suggest that you look at this closely as a possible cause.
    Saturday, July 18, 2009 4:45 PM
  • Mine magically started working. Not sure why as I didn't do anything differently. The memory timings are different for the sticks I used, I just made sure I installed them into the correctly paired memory slots.
    Tuesday, July 21, 2009 7:08 PM
  • I have a Dell Vostro 200 and I had the same issue until I updated the BIOS. I was pretty frustrated after buying 4 GB of Corsair Memory and Jumping from 3 GB to 3.25. I can now see all 6 GB. Thanks for the suggestion.
    Thursday, August 13, 2009 8:36 PM
  • Check your BIOS in advanced tab or chipset and determine if there is setting to enable memory remapping. This is needed for 64-bit OS.
    ASUS P4PE-P4 Extreme 3.4gHz-2gb G.Skill PC3200-XPSP3:55gb-Win7RC:17gb-DATA:500gb-ASUS N6800GT
    Friday, September 11, 2009 12:54 PM
  • First you should enable the Memory Remapping feature in order to get the more than 4GB of of Usable System Memory
    Go to the BIOS (press the F2 DEL when the BIOS booting) then go to Advance BIOS feature (it may be change BIOS to BIOS) or Advance Chipset Feature or Similar
    then Enable the Memory Remapping so you can enable More usable Memory if you have a 64 bit Processor and 64 bit Operator System I guess it works with Only
    Windows XP or Later OSs.!
    Tuesday, November 3, 2009 1:31 PM
  • Im having the same promlem with Windows 7 64bit it registers 4GB (3.55 usable).  I tried enabling memory hole in BIOS which seemed to fix it, it shows up as 4GB but this leads to me having a crash to BSOD saying "a clock interrupt was not received on a secondary processor with in an allocated time interval"  This happens only when memory hole is enabled but thats the only way i could get all 4GB to show. Is anyone else having this problem or know how I can sort it?
    Thursday, June 24, 2010 6:33 PM
  • NVM  I think this is due to my new motherboard's auto settings being totally off. I just noticed it didnt even detect my ram properly.
    Friday, June 25, 2010 10:39 PM