Bios not detecting all memory

[YatMeister]

Hi

I have recently built a new PC and am having an issue with the detection of memory. I installed 2 x 2gb sticks, however the BIOS only sees 2040MB of memory - not even a full 2GB's.

Key system specs are as follows:

O/S - Windows 7 64 bit (business edition)
Mobo - Asus P7P55D-e pro
Mem - OCZ DD3 PC3-12800 1600MHz (OCZ3G1600LV4GK)
CPU - Intel i5 750
GPU - XFX ATi 5870
PSU - 750W XFX

System information within the O/S shows only 2GB of memory. I have run CPUz however, and this is able to detect the full 4GB's.

Steps i have taken: updated the BIOS; removed and reseated the CPU (twice); removed one stick of memory; changed the slots the memory were sitting in and shouted at the computer a bit!! After every change it still shows 2040MB of memory.

Has anyone got any suggestions on what could be causing this problem / how to resolve it?

Apologies if this thread exists elsewhere - I couldn't find it.

Cheers

NOTE - my motherboard does not support 1600MHz in dual channel mode (I wish i knew that before purchase) so am running the modules in different channels.

 

[paparazi]

Unsupported or incompatible ram....often this is rectified with a bios flash which improved ram compatibility.

See the manufacturers bios history for this model and read the improvements between bios files. One of the common improvements is better memory compatibility.

Martin

On wings like angels whispers sweet
my heart it feels a broken beat
Touched soul and hurt lay wounded deep
Brown eyes are lost afar and sleep

 

[danomac]

I've also had issues with OCZ ram. My BIOS allowed me to change all the timings and memory voltages manually, and once I'd done this both sticks of ram both worked and was stable.

Do check the BIOS revisions. One thing I've noticed about OCZ DDR3 RAM is that it's voltage *needs* to be higher than the default usually set in the BIOS (iirc mine had to be 1.8V, and the board always wanted to use 1.5V.

 

[cdogg]

I'm not sure if it makes a difference or not, but the Core i5 750 processor only supports the 1333MHz speed for RAM in dual-channel. You might want to make sure the 1600MHz memory you installed is being clocked appropriately down to 1333MHz in the BIOS.

~cdogg
"Insanity: doing the same thing over and over again and expecting different results." - Einstein
[tab][navy]For posting policies, click [/navy]here.

 

[YatMeister]

Thanks all for suggestions. I have managed to get it to work, though not exactly sure what fixed it!

I disabled quick boot and also moved the modules so they were sitting next to each other in the 2nd bank of dimms (so 3rd and 4th slots on the board - in different channels) and it now fully detects all the memory. I wonder if the issue was due to the RAM not being seated correctly or perhaps a broken dimm slot? Surprised I didnt pick this up earlier though considering how often i moved the memory about!

Thanks for tips on setting the correct voltage and speed for the memory - that will be the next step. Its currently only running at 1066MHz.