Windows 7: 12Gb suddenly shows as 8Gb!

First my specs:

i7 920 @ 4.0GHz
3R Systems Prima Boss II 120mm CPU cooler
Asus Rampage 2 Extreme
12Gb GSkill DDR3 12800
Palit 4870X2 Revolution in CF
150Gb WD Raptor
300Gb WD VelociRaptor
1000Gb * 2 WD Caviar Black
1000W NC Top
Heroichi Cougar Big Tower
Windows 7 Ultimate RTM x64

Hi There,

I recently upgraded MB, RAM and CPU two months ago (new). After clean install of Windows 7 everything was working just great!

This afternoon, CPU meter in sidebar, system performance info (in control panel) and BIOS shows 8Gb! Funnily enough CPUz still shows 12Gb.

Removing 3 channels of memory and rebooting resulted in....NOTHING. No beeps, no BIOS posts-just a black screen with a "locked" message on the BIOS LED.

Trying 1 stick, 2 sticks, 3 sticks (in combo) resulted in the same result-NOTHING. 4 sticks worked but showed up as 4Gb, 5 sticks 6Gb ad 6 sticks 8Gb. Clearing CMOS faired the same results.

I have OCd the CPU to 4.0GHz WITHOUT altering voltages (all settings on auto)

What could be the problem? Bad sticks?

Thanks in advance!

H

If you have a setting called max memory in BIOS, it should be unchecked

Check this setting in MSCONFIG

Start
Run
msconfig

.

Hey there ZigZag

Thanx for the quick turnaround.

Unfortunately nothing in BIOS to that effect.

Have read about your suggestion in other forums

I presume that you have 6 sticks of 2gB each?
Have you tried a memory test with all sticks installed?
Have you tried resetting the BIOS to Fail Safe values?

If RAM sticks fail, you will have bigger problems than a disappearing total amount value.

Check msconfig for boot setting limitations. This is your first test, without exception.

Well, one exception - if someone physically removed the sticks.

Hi there guys,

Just wanted to thank you for all your assistance.

Checked msconfig and checked BIOS. No luck.

I took out all memory and installed one by one in sequence.

2Gb each in slots 2, 4 then 6 (consecutive reboots).

Another 2Gb in slots 1, 3 (total 10Gb confirmed in system and CPUz).

However back to 8Gb after inserting last stick in slot 5!

I exchanged this with stick from slot 4 and system/CPUz recognized 6Gb!

I think one stick is bad which I will RMA tomorrow.

However I don't understand why this "bad" stick will subtract an extra 2Gb. ie, 5 good +1 bad stick registers as 8Gb usable, 4 good +1 bad stick registers as 6Gb.

Anyways, thanks again.