Crossfire does not work anymore!

[Lateralus180]

I am having problems with crossfire and my two XFX 5870's. When I built my PC two weeks ago, crossfire worked fine. I maxed out Bad Company 2 and I remember getting 70-120 frames. I'm not sure what I did, but I am getting 45-75 now. I did tweak some things in CCC so I thought the drop was something to do with AA / AF settings, until I removed the second card to test.. :shock:

Running with the 2nd card removed, I was getting the exact same frame rate in BC2. Same settings, same range. I checked the power connections for both cards, and all four 6-pin cords work fine with both. I even checked both cards running solo in slot 1, and they both work. When I pair the two up and connect the crossfire bridges the same way I did on the initial boot up two weeks ago, I have no fps gain in game. "Enable Crossfire" is checked off in Catalyst Control Center..

CCC does detect the 2nd card and the crossfire page shows. Under the ATI Overdrive page, I can view/change settings for card 1 and card 2. Card 1 displays the current clocks, fan speed, and GPU temp. Card 2 has 0's for every value. After cranking the manual fan speed to 100% and applying the settings it does nothing. Between my initial build and now I did install an XFI card, around when I noticed the FPS drop. I removed the card to test if that was the problem, and the rate did not change so I can rule that out.

I know for sure the card works and is not defective. The problem must either be something in BIOS that doesn't allow for two cards, or something in Catalyst Control Center.. Any and all help is appreciated!

ASUS P6TD Deluxe
Core i7 930 2.8 GHz
6 GB 1600 MHz RAM
Two XFX 5870's crossfire'd
Thermaltake 850 PSU
128 GB SSD

[Lateralus180]

I have tried everything to see what affects my frame rates. The first few days after building my PC I had Catalyst AI enabled, and I had very high frame rates in BC2. I also had an annoying flicker in the game so I disabled the AI. My frame rates dropped down to where they are at now.. By the looks of things, CrossFireX was never setup properly. For two weeks now I thought crossfire was working as intended, but now I am noticing the exact same frame rate with a single card vs two cards. How the **** do I get this to work?!


EDIT:
What a big headache! Apparently disabling Catalyst AI 'disables' the performance gain from crossfire. No one told me this! Problem solved-ish.

I am noob.

[wingman99]

Remove your drivers and use DriverSweeper then reinstall your drivers:cool:.

[Brutal-Force]

Remove your drivers and use DriverSweeper then reinstall your drivers:cool:.

Yup. Crossfire/SLI sometimes have issues with getting both cards to be seen. Uninstall and delete drivers, then reinstall new drivers, then reboot.