[QUOTE="hartsickdiscipl"][QUOTE="oOiRuL3zOo"] the second PCI-E 2.0 port is only x4 speed and the first port is x16, wont the second port slow down the Crossfire process?oOiRuL3zOo
It depends on what kind of GPUs you put in that rig. This article shows that an x4 slot only slows down a 5870 by 5 to 8%.
http://www.techpowerup.com/reviews/AMD/HD_5870_PCI-Express_Scaling/
I think one of these budget Crossfire mobos with the 2nd x4 slot would be great for a pair of 6850's.
I wanna make sure we're on the same page, I mean x4 as in the speed and not the size of the slot, and yes I was going to Crossfire 2 6870's but some told me to wait for the 6890 just incase.I wouldn't crossfire 2 cards that are any faster than a 6850 in a board with an x4 slot as the secondary. Yes, I know the 2nd PCI-E slot is a full-length slot, but running at x4 speed. My motherboard has the same. Since the 6870 is only a bit slower than a 5870, and we can see the 5870 losing a bit of performance over the x4 bus, I'd have to assume that the 6870 would lose a similar percentage of performance. The 6850 seems to fall right on the line where you wouldn't lose much performance. That's just my interpretation of the numbers. If I were going to buy a pair of 6870's ($240 US each), I'd probably get a motherboard that would run both cards at either x8 or x16.
Once again, that's just what I would do. I'm sure the x4 slot won't be a massive bottleneck to the 6870's.
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