Folks, I just bought my first dual gfx card computer--two 6850s sitting in a MSI 790FX-GD70 motherboard. Does it matter which two PCIE slots I use? They're all the same speed, but someone told me that for true crossfire you must use PCIE 1 and PCIE 3. The problem is that the crossfire cable I have will not reach that far! I can do slots 1&2 easily, but it just plain won't reach all the way to 3! Am I boned?
There should be two crossfire bridges inside the motherboard box, those are long enough to reach to the third slot ( I have the same motherboard)but the ones that come with the gpus mostly aren't.
The fact that slots 3 and 4 are x8 doesn't mean the cards will run at half their speed, there's only 2-3% difference in performance, actually most motherboards are only capable of X8/x8, only a handful of boards like the GD70 are capable of full x16/x16.
Thanks for the reply, Wii! I thought there were supposed to be crossfire cables too, but there were none in the box... No stores around here carry them, either. Ah well, I suppose I'll have to order it and wait.