Radeon 7970: dual 16x vs. dual 8x

A difference of ~10% between the 2 configurations I would say. The 7970 will fully saturate the x8/x8 slots in some cases - especially when overclocked.

7970 is a high end card, therefore it's most likely to have full bandwidth of 16x/16x to work %100 without bottleneck. If you want a board that has x8/x8 (PCI-E 2.0 mostly) I'd recommend you to get x16/x16 instead.

Yeah but if as deadjon said the difference is only a minimal 10% I'd stick with the 8x speeds. For now anyway I'm going to use a single card which will run at 16x and that should be more than enough for the time being. If I want a dual 16x I would also need to get a x79 board which runs on the overpriced i7-3960 since the intel socket 1155 boards I'm looking at don't apparently support dual 16x speeds.

Btw the slots will be 3.0 dunno if that makes a large difference to a 8x speed 2.0 slot...

This is PCI-E 2.0, Ivy bridge has not been released yet.

I would suggest looking at the GTX580 test for x8/x8 and figuring it out from there.

The 7970 is 10 to 20% faster than the GTX580 3GB @ Stock speeds I believe.

I don't understand "This is PCI-E 2.0", the bandwidth is 16GB/sec, how can PCI-E 2.0 support that?

The difference between x8/x8 and x16/x16 is about 4-5 FPS http://www.tweaktown.com/articles/4147/nvidia_nf200_x16...

Yeah looked at the link from FunSurfer, the difference between a pcie 3.0 x16 vs. x8 is nothing much.

Best answer selected by tha1.

This topic has been closed by Mousemonkey