[solved] ASUS M5A99FX Pro R2.0 not using all 8GB of Memory

The motherboard recognizes all 8GB in the 2 slots, A2 and B2, but it says only 3.9 GB are usable.

In CPU-Z, it says I have 8GB but it says I'm running in single channel. This isn't an OS issue because it's Windows 7 64 bit. Pls halp.

Have you put the RAM into the correct slots on your mobo (as indicated by the mobo manual) for dual channel mode?

have you tried booting up with only each stick to see if 1 of them is defective

I think you may want to try and take them out and put them back in make sure they are all the way in.  Also check the manual for you mother board to check what slot slots are dual channel.  Generally its every other slot for dual channel.  The number that counts is what windows recognizes and can use.

I did. A2 and B2.

I'm pretty sure they're in because BIOS sees all 8GB. But for some reason, only 3.9GB is usable.

Sounds like a faulty dimm to me.

Go to: Msconfig  > Boot tab > advanced options > Disable max memory.

Reboot.

Grtz Angel ☺

+1

No need. Fixed it. Took out the sticks. Reseated them. Problem solved. ragingh4vok is a prophet.

That´s great ☺

Then i put a lock on this thread.

Grtz Angel ☺