ASUS M5A99FX Pro R2.0 - Issues with memory slots.

[KokoroAkechi]

I recently got this motherboard and I noticed on the boot menu it only was using half my ram (4GB/8GB). I ran a mem test on my ram and none of them work on the first two slots. They are work on the last two.

On the system information it says 8.00GB (3.90GB Usable). The BIOS menu actually knows all 4 sticks are in but only half of it is actually installed. It does not matter what order my ram sticks are in when I do this.

Specs
Windows 8 Pro 8.1
AMD FX-8320
ASUS M5A99FX Pro R2.0
Nvidia GTX 560ti
Corsair TX750
RAM: G.Skill F3-10666CL9-2GBNS X 2
RAM: Wintec 3AXH1333C9WS4GK X 2
(I've used this ram set up in my last machine. The clock speeds etc are the same)

I'm on BIOS 2005.

 

[Quaddro]

Any 32bit operating system architecture is limited to 4Gb ram..

if you have more than 4 gb ram and you want to use all of it, then you have to upgrade your operating system to 64bit version...

 

[KokoroAkechi]

Oh. It appears I didn't mention. I am on a 64 bit operating system.

 

[Quaddro]

are your sure..?
"On the system information it says 8.00GB (3.90GB Usable)" => this is only happen if you're using more than 4gb memory in 32 bit operating system..

But if you sure enough..
Then try to clean the golden bridge memory and your memory socket with contact cleaner..

 

[Tradesman1]

If the cleaning doesn't work would suggest checking the CPU and socket for any thermal compound, debris and most importantly bent/broken pins

 

[KokoroAkechi]

I checked the components and nothing seems wrong. The BIOS only says 4GB. I think I just have a bad board.

 

[Tradesman1]

May well be 🙁

 

[Calvin7]

RAM: G.Skill F3-10666CL9-2GBNS X 2
RAM: Wintec 3AXH1333C9WS4GK X 2

That is three kits, two single and one pair. Nobody guarantees that kind of mixture to be compatible. While there is always a possibility that it may work, you shouldn't count on it. It is recommended to use just one kit. You might think you are saving money by combining kits but often they have compatibility problems as they haven't been tested together.

 

[KokoroAkechi]

I've used this combo on my previous board (as mentioned). I can boot from the two good slots with any combination of ram I want. I can't boot at all from the two bad slots. It is not even the A1 and A2 or B1 and B2 slots that are not working. It's the two next to each other farthest from the CPU.