Originally Posted by arrow0309
Maybe it's the pci-e volt?
How about your cf pci-e bandwidth? Did you have a 32x (16x/16x) before and got an 8x/8x now (for the 6850's)?
PS: I've recently set the oc freq. for my two 6870's not anymore synchronized with the afterburner, 980/1200 for the top Hawk and 1000/1140 for the bottom one. It seems it works pretty good with Batman AC so far. Is there any particular reason why we shouldn't run our cards at different speeds?
Yes I did go from 16x/16x to 8x/8x but that doesn't hurt performance at all.I used to run both 6850's ,my gtx 260 for physx, and my 8500gt as a tv card and got very similar benchmark scores a little lower than just the two 6850's at 16x/16x (My board does 4 pci-e slots at 8x).But after raising the pci-e voltage the scores were exactly the same so I can tell you for sure (because ive tested it) a 6850 overclocked or not can't saturate the x8 bandwidth.The only reason I raised the voltage was adding another card but Im starting to think it also helped my overclock.
The only thing ive noticed running the cards at different speeds is the card with the higher clocks usually has lower load and because of this I think you get even performance.I personally never tried but do you get higher scores with say 980/1200 and 1000/1200 vs 980/1200and 980/1200?Id figure that because the card with the higher clocks doesn't load as high its the same as running them both at the same speed but im guessing here.
I stopped running the cards at different speeds a while ago because afterburner won't let me anymore.lets say I set profile #1 on card #1 to 970/1100 if I set profile #1 on card #2 to 1000/1100 then profile #1 on card #1 will revert back to stock 790/1000..
Im not worrying about it anymore because now both cards can do 1000/1100 rock solid and stay cool.Im a happy man no more afterburner voltage mod no unofficial overclocking and ulps is still on I may try to push the vram a little but other than that im good.Edited by smoke420 - 3/19/12 at 8:16am