CPU-Z recognizes 16gb of ram, BIOS/Windows only recognizing 8gb

[bluecrush]

Backstory:

I originally had 2x4gb ram sticks, which was working perfectly fine. My friend upgraded his computer, so he gave me his spare 2x4gb sticks. I inserted it into my mobo, did not adjust anything in the bios, and everything was working perfectly fine. Windows was showing 16gb.

However, couple days ago, i noticed windows was no longer recognizing 16gb. It only showed 8gbs.

I have 4x4gb ram sticks, CPU-Z recognizes all 4x4gb sticks, but bios/windows only shows 8gbs. However, my bios seems to be able to recognize that there are 4x4gb sticks inserted in the slots. Also, I have not overclocked anything.

Below are my specs:
OS: Windows 7 64bit Professional
CPU: i5-3570k 3.4ghz
Mobo: Asus P8Z77-V LK
Ram: 2x4gb G.Skill Rip jaws pc3-12800 9-9-9-24 & 2x4gb G.Skill Rip jaws pc3-12800H 9-9-9-24
Graphics: Radeon HD 6450
PSU: 400w Corsair CX400

Pictures of CPUZ and BIOS

Things I've tried so far:

Reset BIOS to default settings, and cleared RTC RAM.

I've tested all slots and ram, and I'm pretty sure they all are working.

I've tried inserting 2 sticks (sticks A and B), and I get 8gb. I try add another stick (stick C), but it still only shows 8gb. So I remove A and B, and try sticks C and D, and bios shows 8gbs. Then I try add stick A to the mix, but bios again only shows 8gb.

I've also tried the sticks in another computer and the bios shows 16gb on that computer. So it appears that the ram sticks aren't the problem.

I tried swapping my PSU with a 600w PSU, but bios still only shows 8gb with 16gb inserted.

Any suggestions for what I should do? Would updating my BIOS help?

Thanks

 

[brispuss]

Bump the DRAM Voltage up by 0.05 V.

If that doesn't seem to help, increase VCCSA Voltage by 0.05 V also.

 

[bluecrush]

Bump the DRAM Voltage up by 0.05 V.

If that doesn't seem to help, increase VCCSA Voltage by 0.05 V also.

hey bripus, thanks for the suggestion.

I tried bumping up the dram voltage by 0.05V and VCCSA by 0.05V but its still only showing 8gb. Any other suggestions?

 

[bluecrush]

Bump the DRAM Voltage up by 0.05 V.

If that doesn't seem to help, increase VCCSA Voltage by 0.05 V also.

hey bripus, thanks for the suggestion.

I tried bumping up the dram voltage by 0.05V and VCCSA by 0.05V but its still only showing 8gb. Any other suggestions?

 

[brispuss]

Try increasing VCCSA Voltage again by another 0.05 V.

 

[bluecrush]

Try increasing VCCSA Voltage again by another 0.05 V.

So I tried bumping VCCSA voltage by another 0.05V but windows still only shows 8gb. I'm starting to think maybe my mobo may be faulty? Or could the CPU be causing issues?

 

[brispuss]

OK. Check that the CPU and it's cooler are mounted evenly with respect to the motherboard, by loosening the CPU cooler mounting screws etc and resettling the CPU cooler on the CPU. Re-tighten the CPU cooler mounting screws so that the CPU cooler should be sitting evenly/flat on the CPU and not sitting slightly lop sided.

Another check is to confirm that TWO identical memory modules (8 GB in total) work in any combination of memory slots (ie slots 1,3; then slots 2,4; then slots 1,2; and finally slots 3,4).

 

[HvStV]

OK. Check that the CPU and it's cooler are mounted evenly with respect to the motherboard, by loosening the CPU cooler mounting screws etc and resettling the CPU cooler on the CPU. Re-tighten the CPU cooler mounting screws so that the CPU cooler should be sitting evenly/flat on the CPU and not sitting slightly lop sided.

Another check is to confirm that TWO identical memory modules (8 GB in total) work in any combination of memory slots (ie slots 1,3; then slots 2,4; then slots 1,2; and finally slots 3,4).

why not 2,3 and 1,4? Just wondering.

 

[brispuss]

Testing memory in slots 1,3 and then slots 2,4 tests dual channel function. Testing memory in slots 1,2, and then slots 3,4 tests single channel function. Alternatively, could test memory in slots 1,4, and then slots 2,3 instead of slots 1,3, and then slots 2,4, but this is just another way of testing dual channel function.

However, if want to be absolutely certain of testing ALL possible combinations of memory in slots (using two modules), then slots 1,4 and then slots 2,3 can finally be tested also. Although the possibility of memory/slot faults appearing after testing slots 1,3; then 3,4; then 1,2; and then 3,4 is very small. But there might be a remote possibility that faults may not show until the two modules are tested in slots 1,4 and then slots 2,3.

 

[bluecrush]

Hey brispuss, thanks for the continued suggestions! I will give these a try when I have some free time. I'll post an update after I get a chance to try your suggestions.

 

[bluecrush]

Testing memory in slots 1,3 and then slots 2,4 tests dual channel function. Testing memory in slots 1,2, and then slots 3,4 tests single channel function. Alternatively, could test memory in slots 1,4, and then slots 2,3 instead of slots 1,3, and then slots 2,4, but this is just another way of testing dual channel function.

However, if want to be absolutely certain of testing ALL possible combinations of memory in slots (using two modules), then slots 1,4 and then slots 2,3 can finally be tested also. Although the possibility of memory/slot faults appearing after testing slots 1,3; then 3,4; then 1,2; and then 3,4 is very small. But there might be a remote possibility that faults may not show until the two modules are tested in slots 1,4 and then slots 2,3.

So I tried slots 1, 2 and it only read 4 gb. I then tried 3, 4 and it also only read 4gb. Afterwards, I tried slots 1,4 and 2,3 and they both showed 8gb.

It looks like its an issue with single channel?

 

[brispuss]

Did you try re-seating the CPU cooler? If not, then suggest that this be done, and make sure CPU cooler is mounted evenly.

 

[bluecrush]

Did you try re-seating the CPU cooler? If not, then suggest that this be done, and make sure CPU cooler is mounted evenly.

Sorry for the late reply, been super busy.

Anyway, so I first tried swapping out my CPU with a spare CPU and it still only showed 8gb.

Afterwards, I swapped the CPU back and re-applied thermal paste, and re-seated the CPU cooler making sure it was evenly mounted. Unfortunately, it's still showing 8gb.

Is it safe to conclude that there is an issue with my motherboard? Thanks again for your help so far brispuss.

 

[brispuss]

From all the testing done, unfortunately it appears that the motherboard may be faulty. Can't think of anything else which may be causing the memory issues.

 

[bluecrush]

From all the testing done, unfortunately it appears that the motherboard may be faulty. Can't think of anything else which may be causing the memory issues.

Yeah I was hoping that wouldn't be the conclusion, but that is what it appears to be.

Anyway, thanks for all your help brispuss!

 

[voodoonet]

hello, I too have the same your same problem but with the same memory, yesterday my pc started to read only 8gb but the BIOS reads the 1x4gb regular slot on all slots but the total shows only 8gb.
cpuz reads 16gb, but the system and the bios reads only 8gb. And 'the main board? or memory?

Google translator from Italian

 

[williamslijp]

i bet igpu configuration menu wont show up in bios, mother board problem, same shoes as your guys. check this post out.
http://www.tomshardware.com/forum/348844-31-build-problem-3770k-igpu-lucid-logic