7970 crossfire probs

currob · 16 May 2012 at 11:40

Hi, I've recently added a 2nd 7970 to my system. Uninstalled all drivers and profiles and reinstalled them, but the second card will only run at pciex16@x1 under load. When starting a benchmark/game it throttles up to full speed then within seconds drops to lowest clock settings. Using gpuz it shows it is only running at x1 even during stress tests. Any ideas anyone please? My mobo has a pcie x16@x16 slot and a pcie x16@x4 slot (this is the one that only runs at x1 at the moment)

eyetrip · 16 May 2012 at 11:43

Check in your BIOS. There should be a setting to choose speed of 2nd slot.

This is probably on auto - try setting to fixed 4x

currob · 16 May 2012 at 11:45

ok, thanks, will try it now

currob · 16 May 2012 at 11:55

Darn, been through all menus in bios, no settings available for that

eyetrip · 16 May 2012 at 11:57

What board is it?

currob · 16 May 2012 at 12:01

ASUS M5A97pro (AMD970 / SB950)

whitestar85 · 16 May 2012 at 12:08

Does the pci slot share bandwidth mines 4x but if I use pcie 3 drops to 1x had to juggle some components round

currob · 16 May 2012 at 12:12

Would it share bandwidth with sata devices?

whitestar85 · 16 May 2012 at 12:19

Are u using the pcie slots ? Maybe remove what's in them just to eliminate pci bandwidth sharing I'm not sure on the sata side of things sorry, il go look what mi e reads in gpu z idle/load

currob · 16 May 2012 at 12:39

Ok, moved the sata's around a little too, no other cards installed, still same result one 7970 @x16 the other @x1

whitestar85 · 16 May 2012 at 12:46

Just checked my gpu z it reads 2.0 4x on second card even when no load, what are your ccc settings ? Crossfire enabled etc

currob · 16 May 2012 at 12:49

Yes, crossfire enabled in ccc and all other settings on default (clock etc..) and gpu-z shows 2 gpu's enabled but also says "ULPS active" - i don't know what that means -googling it atm

whitestar85 · 16 May 2012 at 12:53

Something to do with power saving u can turn it off somewhere in the registry so I would do that. It's only changing a 1 to a zero takes about ten seconds,

Surveyor · 16 May 2012 at 12:58

Hi currob.

Please fix your sig.

Only 4 lines of text are allowed.

currob · 16 May 2012 at 13:06

ok, part way there now, disabling power save has sorted the pcie bus out, now have both cards operating at pcie 2.0x16 with card one at x16 and card two at x4. However, card two is not sharing any of the gpu load and not throttling up to speed

eyetrip · 16 May 2012 at 13:09

Remove one card

Uninstall drivers and reboot

Reinstall drivers and reboot

Shut down, add 2nd card, and see what you get...

Know this has worked for me in past.

whitestar85 · 16 May 2012 at 13:15

I only play bf3 ATM but using the default profile for cf gets like weird load amounts bf3 one gets about 95 per card and is smooth no mad stuttering

currob · 16 May 2012 at 13:21

sorry to ask another noobie question, just doing the uninstall advice from 'eyetrip' and noticed 2 crossfire connectors per card - should i have 2 crossfire bridges connected?

whitestar85 · 16 May 2012 at 13:27

No 1 is fine

currob · 16 May 2012 at 13:41

ok, done the uninstall and reinstall but 2nd card still not taking any load and remaining at gpu clock of 300mhz. Bench results are much lower than just one card installed