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PCIe 2.0 x8/x8 vs PCIe 1.0 x16/x16

Last response: in Graphics & Displays
March 11, 2009 5:05:23 PM

I have a slightly older motherboard (ASUS A8N32-SLI) and 2 EVGA 8800 GTS 512MB cards. I know the cards I have support PCIe 2.0, but the mobo only supports 1.0[a?] -- on the plus side, though, the mobo does support full dual x16/x16 in SLI.

So, I'm looking to possibly upgrade my mobo/cpu/ram from 939/Athlon X2/DDR to AM2+/Phenom/DDR2. However, I've discovered in my research that most reasonably-priced mobos with 2 PCIe 2.0 x16 slots can only run dual x8/x8 in SLI.

My question is this: from a purely graphics-oriented perspective (ignore the boost in cpu and ram from a new mobo), which is better - PCIe 2.0 x8/x8 or PCIe 1.0 x16/x16?

More about : pcie pcie x16 x16

a c 165 U Graphics card
March 11, 2009 5:16:28 PM

Neither, PCI-E 2.0 is twice as fast as PCI-E 1.0/1.0a so you`ll have the same bandwidth with either setup.
Unless you plan on some very powerful upgrades to the graphics (a pair of GTX285 or more) you`ll not need more bandwidth than is already available.
March 11, 2009 5:47:30 PM

Yup, the bandwidth from each is the same, the only reason the PCI 2.0 system would likely perform better are either cpu upgrade, ram upgrade, or using a single card a few years from now (as 16x PCI 2.0 is 2x as fast as 1.1).
March 12, 2009 12:28:03 PM

SLI pci-e x8 and x16 have less than 5% difference in actual performance. Even pci-e x4 most of the times performs around x8, only sometimes falling largely behind.