BIOS detects 4GB RAM, WIndows detects 2GB.

[SeanGilbreth]

When building my computer, I made sure that I was future-proofed in terms of RAM, so I installed 4GB of RAM (4 x 1GB sticks). My problem is that Windows only detects 2558 MB not the full 4096 MB. I find this very odd, as my BIOS reads that I have 4GB, but Windows doesn't. (BTW, this was the case with XP and Vista).

Can anybody suggest a solution?

Thanks for any help!

 

[stduc]

What kind of RAM sticks do you have?

From the manual

Normally, the memory timing is set at 2T but to enhance system
performance, the default memory timing has been fixed at 1T
(Command Per Clock: Enabled). Therefore if you use 4 single side
DIMMs, the load will exceed the limit (DDR 400). Please refer to
the steps below to solve this problem.
1. Set the "DRAM Voltage Control" field (in the Genie BIOS
Setting of the Award BIOS) to "2.8V".
2. Set the memory timing to 2T by selecting Disabled in the
"Command Per Clock" field (in the Genie BIOS Setting of the
Award BIOS).

Memory Hole for PCI MMIO

Usually enabling this permits more than 4GB of RAM - so you should not need this setting.

However

Leave windows out of the equation for now. It will just confuse the issue.

Once you have got through a full memtest86 test sequence without problems using all 4GB you can be sure that your DRAM refresh, timings etc etc are fine. Not optimal maybe - but fine. (i.e. metest86 sees and tests all 4GB)

Then you can sort out windows. XP has problems seeing above 3GB - the /3GB switch will definitely help (probably).

 

[wahnula]

the /3GB switch will definitely help (probably)

PAE /3GB switch in boot.ini is imperative, but I agree to leave Windows out of the equation until all 4GB are visible in BIOS.

Tony

 

[SeanGilbreth]

Sorry to pass over everyone's posts like this, but I disabled SLI Broadcast Aperture, and the BIOS tells me I now have 3.9GB of memory (Windows says 3.75GB). It seems like I may have to disable something else aswell, would anyone know what it could be?

 

[wahnula]

Hey, keep going, you will have 5 GB soon

Look in AMD forums for more BIOS tweaks.

Tony

 

[cdogg]

DakotaXS,

You need to try stduc's suggestion in his last post. Fumbling around in the BIOS is senseless, and you don't know what you are enabling or disabling. In fact, you could be destroying your system's potential just to get to the magic number of 4GB.

Reset everything back to the default and try setting 2T. That is a common issue with an easy fix.

~cdogg
"Insanity: doing the same thing over and over again and expecting different results." - Albert Einstein
[tab][navy]For general rules and guidelines to get better answers, click here:[/navy] faq219-2884

 

[cdogg]

I actually did a little digging myself. What stduc posted was from the "Frequent Q&A" section of your manual on page 7.

Below is from pages 20-21:

Configure the system memory in the Genie BIOS Setting submenu (“DRAM Configuration” section) of the BIOS...

The integrated memory controller in AMD's 64-bit Socket 939 series CPU will directly catch data transmission from DDR RAM without passing through the Northbridge. Therefore when using 4 identical double side DIMMs or using 2 DIMMs in non-dual channels, the memory speed will reduce to DDR333. Please refer to the detailed memory speed shown below...[see manual]...

A DIMM's SPD is originally fixed at 1T. When modules are inserted in DIMM 1 and DIMM 3, the SPD must be 2T for better system stability. We recommend inserting DIMMs in DIMM 2 and DIMM 4.

Again, try setting 2T and see if that helps.

~cdogg
"Insanity: doing the same thing over and over again and expecting different results." - Albert Einstein
[tab][navy]For general rules and guidelines to get better answers, click here:[/navy] faq219-2884

 

[teknikal]

I agree. I've had that issue before and had to set 2T instead of 1T when I had more than 2 DIMMs.