Question on 7970 CrossFire

RaistlinZ

Diamond Member
Oct 15, 2001
7,470
9
91
I just hooked up my two Sapphire 7970's. I endabled CrossFireX in CCC and it seems to be working correctly. However, in GPU-Z when I check the second GPU it shows it running at 32bit memory bus instead of 384bit like on GPU 1.

Is this just a glitch in GPU-Z, or is my second card now working properly? I ran 3D Mark Vantage and got 36,000 or something compared to 26000 with one 7970. But Unigine Heaven fps didn't change after installing the 2nd card, so I don't know what to think.

RIFT also isn't showing any fps increase with CrossFire enabled.
 
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jackstar7

Lifer
Jun 26, 2009
11,679
1,944
126
Might be worth flipping cards to check what happens... if it's not a huge PITA.
 

RaistlinZ

Diamond Member
Oct 15, 2001
7,470
9
91
Ok, did a restart and checked my BIOS. My PCIE lanes were set to 16x, 1x for some reason. It's set to 16x, 8x now and both cards show the proper stats in GPU-Z. Hopefully that's all that was wrong.


Nevermind, went back to showing 32bit. :(
 
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SlowSpyder

Lifer
Jan 12, 2005
17,305
1,002
126
For whatever it is worth, I believe CPUZ and GPUZ don't actually report any information pulled from the card. It's really just a database that checks what kind of card you have and pulls the information from it's database. So even if somehow, someway you had a 7970 that did that, GPUZ wouldn't be able to report it. So, it was probably something goofy with the software the first time you looked, a glitch.
 

RaistlinZ

Diamond Member
Oct 15, 2001
7,470
9
91
Hm, so when I try to overclock in CCC do I have to change the speeds on both GPU's or does changing one change them both?
 

RaistlinZ

Diamond Member
Oct 15, 2001
7,470
9
91
Darn it, system still randomly freezing.

I completely uninstalled my previous drivers and installed the 11.12's.

I notice that when benchmarking only the top card is blowing out hot air, the bottom card is blowing out cold air as if it is idle. But my benchmarks are noticeably better when in CrossFire mode so I know the 2nd card is doing something.

Benchmarking works, but system still freezes when gaming or idle on the desktop. Could it possibly be a motherboard conflict with CrossFire?
 

TakeNoPrisoners

Platinum Member
Jun 3, 2011
2,599
1
81
Darn it, system still randomly freezing.

I completely uninstalled my previous drivers and installed the 11.12's.

I notice that when benchmarking only the top card is blowing out hot air, the bottom card is blowing out cold air as if it is idle. But my benchmarks are noticeably better when in CrossFire mode so I know the 2nd card is doing something.

Benchmarking works, but system still freezes when gaming or idle on the desktop. Could it possibly be a motherboard conflict with CrossFire?

Either a CPU bottleneck or V-Sync is on.