Ram issue with Asus board

[breadturbo]

Just bobbing a new mobo in a friends pc for them and i've come across an odd issue.
The machine shows 8gb installed ram but only 3.92gb usable even though it's running 64bit win7?

I've had a look for hardware reserved memory and can't see anything, anyone have any thoughts?

Spec is....

1055t @ stock
2x4gb corsair vengeance 1600mhz
Asus M5a97 le 2.0 (updated to latest bios)
6870

puzzled o.O

 

[wazza300]

boot with one ram stick installed in one ram slot at a time,it should boot from each slot if its all working,if not it could be too tight a cpu cooler or bent cpu pins on amd

 

[Admiral Huddy]

As waaza says, test one stick at a time. Good sure way to test this kind of problem.

 

[breadturbo]

Ty for the help peeps

This gets more confusing, i've tried two sticks of my ram in it and it shows 8gb no problem in any slots, i even tried booting mine with just her two sticks, mine shows 8gb.
tried 1 stick at a time in all 4 slots and both of her sticks work fine solo.
The ram is on the mobo supported list, I didnt put the cpu in so i guess checking that is next port of call.

 

[wazza300]

if it boots from each ram slot with only one ram stick then no need to check cpu socket as everything is working as it should

could be bios incompatibility or something else idk