3GB Ram usable, and only 3GB recognised by BIOS, 4GB installed

[DragonBorn1511]

Hello,

I have a pc here, specs:

E6420 CPU
Foxconn P4M900-8237A Motherboard
4GB(2x2GB)RAM
Palit GTS 450
Windows 8.1 64 Bit

It has 2x2GB DDR2 sticks installed. The BIOS recognizes 3GB, and windows (definitely a 64 bit copy not 32bit) says installed memory (RAM) : 4.00GB (3GB Usable).

This is extremely strange as the system is only recognizing 1 1/2 sticks.....

There's no iGPU that would be using 1GB, and speccy shows 4GB Single channel operation, which shows the dual channel operation isn't working.

I've tired 3 different types of RAM, all matching pairs.

I've reinstalled windows, reseatted the ram. I've even upgraded to a Q6600 from the E6420. And both retain this issue.

I'm really not sure what else it could be, seems to be a bigger problem than windows since the BIOS itself only recognised 3GB.

Any suggestions?

 

[mdd1963]

The BIOS often has options for allocating a certain amount of system RAM to integrated graphics functionality.....even if you are not using it.

 

[ScrewySqrl]

most likely this is a 32-bit operating system, which can address only 4 GB total, usually showing as 3GB and change

 

[DragonBorn1511]

Screwysqrl, as stated in the original post, it's definitely a 64 bit OS, furthermore even if it was a 32Bit OS, that would not explain why the BIOS is only recognizing 3GB total.

Mdd1963, thank you, I will look into this when I get a chance.

 

[DragonBorn1511]

There's absolutely nothing in the BIOS to indicate RAM allocated for integrated graphics or anything else.

Any other suggestions?

 

[Paperdoc]

Try these spots.

Manual p. 35, AGP & P2P Bridge Control - settings for using AGP graphics (you are not) AND for control of bridging among PCI slots

Also items below that re: AGP settings and on p.36, VGA Share

p. 42, "Init Display First" - ensure it is NOT set to try the mobo graphics chip, but does know where your graphics card is.

Try testing your RAM modules. Install only ONE RAM module in one of the slots and check what it says about installed RAM size. Try it in the other slot. Then do the same with the other RAM module. Do BOTH of them report full 2GB RAM in either slot? Or, maybe you have a faulty RAM module. On the other hand, if both RAM modules perform fully in one slot and NOT in the other slot, maybe you have a faulty mobo RAM slot.

 

[DragonBorn1511]

Paperdoc

You've quoted page numbers in your answer does thid refer to the manual for the motherboard, if so where do I find it? Because ive never been able to find it.

Also half the stuff there I couldn't find.

I found the agp and VGA stuff, but not the pci bridge control.

What settings do I use? The display adapter only has option for pciex or pci, It was already on pciex, none of these changed anything, still says 3gb usable, and bios recognised 3gb.

I've tried the sticks individually and they definitely show 2gb each individually, I've also tried 4 different 2x2gb sets, all with the sane result.

 

[Paperdoc]

The AGP and Bridge Control options really are only one setting, it appears, so you don't need to look further. Right now I can't find the mobo manual again, making me wonder if I had the right one in the first place.

Now, what you tell us about testing the RAM modules makes me suspicious. If I read that right, when you try a SINGLE 2GB module in either of the RAM slots the system boots and shows the full 2 GB available. And this happens with BOTH the units you have, PLUS with some others. Yet when you plug in TWO modules, it only shows 3 GB total available. Right? The single-module result suggests that your system is NOT reserving any RAM space for video. Yet 1 GB is "missing" when two modules are installed. AND this happens with ANY pair of RAM modules, correct?

That suggests to me that the mobo is faulty. Or POSSIBLY you have the RAM speed parameters set too high so that it cannot use them correctly.

 

[DragonBorn1511]

Yeah you're right , it's probably broken, so I'm just going to bin it, not worth the tike just for a Q6600 and the maximum possibility of 4GB RAM if it worked.

 

[Paperdoc]

Sorry to hear your problem requires that solution, but I guess it's good to figure out what to do. Thanks for Best Solution.