I have just got my 2nd card to crossfire with my first 6850 and I have run into a bit of trouble with micro stutter. I expected this because my 2nd PCIE slot is an x4 and my first is an x16. I expected the x16 slot to automatically downclock into an x4 when the second card was put in but it didn't. Is there a way to force my x16 slot down to x4 speeds? Hopefully this will help with micro stutter.