my sapphire HD6870 is currently sitting in x16, I am planning on getting another of the same card and crossfire. However the other PCI is x8, will this cause a large decrease in performance? Thanks in advance for your help guys.
Short answer is nope it won't make a difference - you're fine.
Thank you for the prompt reply. Do you think I will have to get some after market cooling for the cards? Or will the stock be adequate?
I will probably have about an inch an a half of space between the cards. I am getting a new case with good air flow (Large fan at front small at back and a top exhaust) and psu at 750w. So I think im finally set!
Thanks for the help.
Best answer selected by numpteyman.
6870 crossfire you will get microstuttering and 1gb is not enough to run modern games with high texture detail, you will get low performance. ive been there done that with crossfire 6850's. a month after i bought the second one i sold them both and went back to a better single card. i didnt believe all the other reports of microstuttering etc, and had to try it for myself. luckily i sold the card for the same price i bought it for on ebay so i had no reall loss, except time wasted stuffing around with radeonpro, and crossfire settings.
I have one at the moment and I can run planet side 2, battlefield 3 etc with high texture detail? So two will be worse then one?