I've installed and reinstalled different versions of drivers and still have the same problem. The box for crossfire under Catalyst control center tab for crossfire, is greyed out. The whole tab dissappears when only one card is in, and both cards work fine individually. Running Cat v7.1 atm. It's like it knows there are 2 cards but I still can't enable the option.
The only set of drivers I couldn't install were the ones that came with the video cards itself. I cannot seem to get by the fact it terminates with the message "Try installing standard VGA drivers before installation", whether or not drivers are already installed. I am stumped. There are no MOBO options for enabling both PCIE slots nor do I need a master/slave b/c its this "native" crossfire.
AMD Athlon 64 X2 4600+
MSI K9A Platinum (ATI xPress 3200)
2GB (1GBx2) Corsair XMS2 DDR2-800 PC-6400
2 HIS Radeon x1650xt IceQ Turbo PCI ExpX16 (bridged with 2 bridges)
Rosewill 550w PS
74G Raptor 10K SATA HD
Just recently I ended up just buying a 7900GS Nvidia card. Granted its not the most savage card but it does just fine for me atm. I have the option of selling off my 2 X1650XT's without trouble so I'm doing that.
ATI support was unable to give me any logical feedback that aided in helping me crossfire (and My System met the Crossfire Specs to the T according to there site)
HIS told me to RMA my cards
ASUS had no useful ideas on this matter either
My supplier had me talk to one of her tech guys and he admitted he had never used Crossfire... only SLI. So all though my board is intended for crossfire I am giving up on it for now.
- good luck with your situation m8, I have found no answers all though I have put many days into figuring out why it would not work on my setup.