I am running a Asus P6x58d MB with two 5870 in Xcrossfire (10.7 Driver). I am having a problem with the Bus Interface speed on my first PCI slot going to x8 after I put my computer to sleep over night. The second PCI slot seems to always be at x16. If I restart the computer it returns to x16 and stays there till I put the computer to sleep again. I am using GPU-Z and CPU-Z and they are both showing x8.
Yesterday I changed my Power Option Plan to High performance and under the Link State Management I made sure it was set to off. I don't believe my MB has any power saver features. The only thing i can find has to do with PCI slots 2 and 3 are the Link Width speed (auto, x8 x8, x16 x1).
It was doing this before I added the second 5870 so that did not cause the problem. Any ideas?
Judging by the fact that slot 1 has no direct control settings, it's default is always x16. It may be an idea to put your cards in slots 1 and 2 (if you haven't already) and to force slot two to x16 mode.
By the way, the real world performance difference between x16 and x8 is about 4% so you're hardly going to see a huge difference in games.