6GB showing as 4GB usable in Windows 7 64bit

Hi Guys

Just built PC in signature and get the above. BIOS says 4088MB usable and Win says 4GB. Bios is 0704.

CPU-Z says i have 3 sticks of 2GB. MemTest (HCI Design) ran for an hour with no error.

What should my next step be please...?

Ta, Mark

Similar issue [thread=18107762]here[/thread]
Unfortunately I don't know of a solution which doesn't feature changing motherboard. I'll keep an eye on these, it seems to be a frequent problem.

Yes i have read a few tales of this but did not want to just start doing stuff without a bit of guidance.

Don't know when to involve OCuk, not sure I want to tinker too much, and bnot sure whether its memory, mobo or chip that might be at issue.

I had a stick go dead recently and while memtest reported its presence I didn't realise straight away that it was only testing 4gb instead of 6! So double check that 6gb is being tested.

When I had this issue changing my mobo and RAM didn't solve it for me.

RMA'd my CPU and mobo twice as well only to have them returned to me found not faulty, and charged for the testing.

In the end I pleaded with the retailer to give me a replacement CPU anyway, which they did, and that did the trick.

However, I also changed my HSF at the same time though after someone else who had the same issues suggested that it could very well be that what was causing the problem, so I don't know for sure if it was the new chip or the new HSF that solved the problem for me.

something about heatsinks without backplates making the board to warp around the socket area which then prevents the pins in the socket from making proper contact with the CPU.

Other things it can be is bent pins in the socket, RAM timings set to tight, not enough Vtt or vDIMM, faulty RAM, or a borked IMC..

hmm was just about to post that I had the exact same problem. its really wierd that cpuz, etc, can see the 3 sticks, but windows can't.
will have to check and see for bios updates, qid, etc.

Try reducing your bclk memory ratio if possible and I bet it reappears.

2:6 always seems stable, just means running memory lower than it's rated, but no biggie in performance terms.

Grimgoth said:

hmm was just about to post that I had the exact same problem. its really wierd that cpuz, etc, can see the 3 sticks, but windows can't.
will have to check and see for bios updates, qid, etc.

Click to expand...

Yep, mine was exactly the same mate.

And I tested pretty much every BIOS for my mobo from F4 to the F8 beta BIOS'es, and nothing made any difference at all.

On the very rare occasion I'd turn the PC on and it would recognize the full 6GB, but shortly after it would crash and then go back to only seeing 4GB.

It did this regardless of whether I was overclocking or not.

There seems to be quite a lot of people having this problem lately, it wasn't a common problem when it was happening to me, it nearly drove me mad!!!

Thank you all for your replies, seems pretty much as i had feared.

Mine has never shown 6GB! whereas others seem to reboot and find it!

Which Memtest should i be running, i got mine from HCI Design, is that the one? Might have a look at the CPU pins, that way i can loosen off the H50.

Are OCuk obliged to ensure this combo works?

ive had this problem scince moving to home premium 64bit.

my threads here http://forums.overclockers.co.uk/showthread.php?t=18105990

however by fiddling around in the bios with memory settings ive managed to got 3.24 usable instead of 1.99. Which is better than it was becasue now i can get around 40-50fps and the occasional dip on GTAIV instead of the constant 60+ i got before

Ive tried booting with different sticks and slot and re seated the CPU a couple of times but nothings worked. Contemplating going back to bios v1.0
see if that helps if not i may buy another mobo, but thers no guarrantee that will work! any how im sick of fiddling so im leaving it at that for now.

I did a bit of googling on this and found the following threads:

http://www.evga.com/forums/tm.aspx?m=119263

http://www.evga.com/forums/tm.aspx?&m=16223&mpage=1

There are a few suggestions on those that you could try, let us know how u get on.

@TomC Ta for the google!

Ah! dxdiag says my Graphics card has approx Total Memory of 2803MB!
So my card is 1GB Memory so how do i get 1800MB back!!!

I have had countless motherboards and memory kits and this has happened for me in all cases when the memory was either clocked too high or the timings were too aggressive.

Be aware that some memory kits might not even be stable at their rated speed.

Ever since the X58 chipset came to market, this problem has existed.
9 times out of 10, or even more, it is down to uneven pressure on the cpu by whatever method of cooling has been used.
If you re-mount the hsf, it will probably cure it. Because the IMC is in the cpu, correct contact between the cpu and the socket pins is critical. It is very very easy to get it wrong, even if you think you have mounted the hsf correctly.

well, after fiddling round last night, mine sees 6GB consistently- I cannot however tell if it was because I reseated the heat sink, or if because I swapped the sticks of ram around a bit.- no bios update available for my board.

My new build is only showing 4gb as well, it's only showing 4gb in the BIOS too.

I dont want to remove the Corsair H50 what do you guys suggest, everything else is running fine.

P6TD MOBO.

How do I set the XMB?

Have you tried underclocking the memory?

Sorry I don't quite have the knowledge to do this yet as i've just built the rig it's taken me most of the day to do it and I have a headache, it's quite stressful building your own.

Can you tell me what I need to do?.

The ram is some Corsair XMS 3 cas 8. 3x 2gb modules.

First things first make sure your memory is running at the correct speed/timings/voltages.

If it still does it try running your memory at a speed slower than it is rated for.

Just load the optimized defaults in your BIOS, this should set the RAM to run at 1066MHz.

However, I doubt this will make a blind bit of difference tbh mate.

There was a couple of occasions where I managed to get my system to POST with 6GB after I removed the CMOS battery and closed the reset CMOS jumper and left it for 30 minutes.

When I removed the jumper and put the battery back in, all 6GB was detected, but after about 10 minutes the system crashed, and when I restarted it only 4GB was showing again.

::edit::

kitfit1 is spot on with his post, I am 110% positive that it was my old Zalman HSF that caused this to happen to me.