Question windows 7 only lets me use all my ram if i down clock it

[AngryPenguin763]

That's right, If I set my ram to the speed to where it's supposed to be, I get 8 gigs unusable in the task manager.
OS windows 7 sp1
Asus Sabertooth 990fx r2.0
Amd 8320
16 gigs evga 1866 sc ddr3
Nvidia 1080
Read a lot of similar issues, tried a bunch of "fixes". So far my only fix is to leave it set to 1333. Yes it's overclocked to 4.8ghz but even at default settings, the only bios setting that seems to affect windows usable ram is my ram set to 1866. Actually anything other than 1333 and when I boot I only get 8 usable gigs. Not cool man..Not fkn cool. It's an odd one. Bios is the latest...umm timings were set to the stick specs. 9-10-9-28 1T. Don't hold me to that, I'm going off memory. ba da bump ... anyway, thx for any help.

 

[kanewolf]

Is this 16GB two DIMMs or four ? FX CPUs would usually only run 4 DIMMs at 1333.

 

[AngryPenguin763]

Is this 16GB two DIMMs or four ? FX CPUs would usually only run 4 DIMMs at 1333.

2 dimms

 

[J_E_D_70]

Matched set in same pack or bought as separate sticks?

Can you increase the ram’s voltage a bit and see if that helps?

 

[AngryPenguin763]

Matched set in same pack or bought as separate sticks?

Can you increase the ram’s voltage a bit and see if that helps?

Matched set, yes, tried voltage bumps and loser timings

 

[Blackink]

So setting the Ram to XMP in the BIOS makes it crash also?

 

[AngryPenguin763]

So setting the Ram to XMP in the BIOS makes it crash also?

No, it doesn't crash but it will only recognize 8 usable gigs of ram unless set at 1333.

 

[Karadjgne]

Have you also bumped up the System Agent voltage in bios when bumping the ram speeds with xmp?

 

[AngryPenguin763]

Have you also bumped up the System Agent voltage in bios when bumping the ram speeds with xmp?

Welp.. Had this mobo 5 years.. I know the bios inside and out..never heard of system agent. Nothing by that name is in there. That might be a Intel thing. Not sure. I've bumped up NB voltage though. That's supposed to help oc'ing ram. I've had this ram to 2400 but like I said..only lets me use 8 gigs when i do.

 

[AngryPenguin763]

Solved: I took the ram out, added another stick and reinstalled it. Seems to be fixed. Makes zero sense but that's what did it.