theoldtime and equinox1, you guys are both bottlenecked by your cpu. Remember how macci SF3D and Sampsa ran their system with 2x 4870x2? Even at 6GHz putting the cards on cold barely helped. The system was still bottlenecked by the cpu!

What i'm trying to say, when you're on the edge of stability you'd better sacrifice some card clocks instead of cpu clocks.