8GB installed, 3.95GB usable on 64Bit Win 7

sreenadh

Honorable
Jul 1, 2012
27
0
10,530
Hello guys,
I just installed Windows 7 Ultimate 64 Bit version on my following PC:

MB: ASUS Sabertooth 990FX (1604 x64 Bios updated - latest)
RAM : 2 x 4GB Corsair Vengeance
GFX Card: ASUS GTX 550Ti


Problem:
Speccy shows 8GB RAM with 2 slots filled out of 4 slots on board. More in the attached pic, and all details.

Speccy image link:
http://tinypic.com/r/125khvp/8

http://tinypic.com/r/10hlzmd/8
&
http://tinypic.com/r/2iut5w3/8

System property pic:
http://tinypic.com/r/2wpjjpe/8


Windows system properties shows only 3.95 GB is usable.

I find this wierd, i tried swapping RAMs among the four slots, tried the MemOK! button the 990FX board. All but in vain.
BIOS shows only 4098MB.

Do any of you know what the problem might be?