you can mine with multiple cards on the same computer without using crossfire ......
....thanks Captain Obvious.
The point I was trying to make was to take 4 shitty processing threads and team them up into 1 SUPER THREAD, so during SHORT ROUNDS IN A POOL your 200Mh/s cards are struggling to make 2 shares/each when the 6990 users have 50+ under their belts in the same amount of time.
GET IT NOW ?