Issue OC'ing RAM

[rstein666]

I just built a new pc and I have 4x4gb Corsair Vengeance RAM. I'm using Asus Sabertooth X79 mobo and Intel I-7 3970x cpu. I'm using the XMP profile in BIOS to oc the RAM at 1600, but when I do the bios and windows says I now have 12gb of RAM instead of 16gb. CPU-Z still shows I have 16gb. I've single tested each stick to make sure they were all working properly and everything goes fine. If I leave the sticks running @ 1333 windows shows I have the full 16gb. I'm stumped, if i just say forget it and run 12gb @ 1600 will it matter that I'm using triple channel instead of quad?

 

[Automata]

When set at the faster speed, how much RAM does it show you have in the BIOS? I'd try reseating the sticks, switching them around, and try slightly raising the voltage to see if any of those help.

 

[rstein666]

Thanks for reply, moved the sticks around and increased voltage in increments until i got up 1.6. Still same story, @ 1333 BIOS and Windows shows 16gb. @ 1600 Bios and Windows shows 12gb and CPU-Z shows 16gb. I assume Mobo slots are good if @ 1333 it recognizes all of the memory and I've tested each stick individually. Not sure whats going on....

 

[dtrunk]

which vengeance kit do you have, they make dozens.

 

[rstein666]

http://www.newegg.com/Product/Product.aspx?Item=N82E16820233235&Tpk=CMZ16GX3M4X1600C9
Thats the vengeance kit i have

 

[RJARRRPCGP]

Thanks for reply, moved the sticks around and increased voltage in increments until i got up 1.6. Still same story, @ 1333 BIOS and Windows shows 16gb. @ 1600 Bios and Windows shows 12gb and CPU-Z shows 16gb. I assume Mobo slots are good if @ 1333 it recognizes all of the memory and I've tested each stick individually. Not sure whats going on....

Apparently, unstable RAM can cause Windows Vista and later to think some RAM is being reserved by the graphics or another device, even when such device don't exist.

 

[Zenos]

... 3970x with vengeance @ 1600...

 

[rstein666]

... 3970x with vengeance @ 1600...

Am I missing something here?

 

[PolRoger]

Have you try giving a bump to Vccio and Vccsa? I take it that any combination of the four sticks from your kit will run 1600MHz just fine in dual channel mode?