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Installed 8GB but only 4GB usable? P55? Read this

Discussion in 'Motherboards & Memory' started by Millennium, Nov 9, 2010.

  1. Millennium

    Millennium New Member

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    I recently got a second 4GB corsair DDR3 kit (2*2gb) to go with my first. Shooting for 8gb, I booted up and it detected all the memory in windows but said 4gb was usable only. In performance monitor I had 4105MB of "Hardware reserved" memory that couldn't be used.

    Strangely the BIOS showed 4 2gb sticks installed but only 2 of them 'enabled'. I didn't have a memory remap option which apparently works for some.

    Googled for a while and found out this is a common problem. So if you have this problem, the fix that worked for me was simple:

    Take out all the memory sticks and put them back in the opposite order. Make sure they are firmly seated and try it again. It should be working now!

    Other things that worked for others are:
    -Reseat CPU
    -Enable memory remapping in AMI bioses
    -in msconfig... boot... advanced disable any checked options (max processors/memory)
    -try different memory or RMA motherboard (last resort!)

    So if this happens to you (and people are bound to want 8gb eventually) I hope this helps. Best of luck...

    Millennium
     
    cadaveca says thanks.
  2. cadaveca

    cadaveca My name is Dave

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    This happens to me when I push FSB over 195bclk. Bios intentionally does it, and IMC volts can affect this.
     
  3. Millennium

    Millennium New Member

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    Strange. I can do 200 bclk with 8gb fine with my mobo now (P55M-UD4)... But I did read somewhere that bclk can cause this.

    Though I had the problem even with stock speeds before I reseated the memory.
     
  4. cadaveca

    cadaveca My name is Dave

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    Well, it says in my board that 200bclk might only work with 2x dimms depending on the DIMM type. I assumed it refered to this behavior.

    But I'm definately gonna check out what you posted...I'm running lower memory speeds becuase of this(it causes crashes), even though my memory is 2000mhz(200bclk), and works fine with just two sticks installed.


    I was really shocked by the notification that all 8GB was there, but only 4GB was usable...
     

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