Is there much performance difference between a 4850 card run on a pci express 1.0 platform and a 4850 card run on a pci express 2.0 platform? I heard that there was a big difference but I just want to make sure since most pci-express 2.0 motherboards that overclock well are much more expensive than pci-express 1.0 boards.
I have a 4870 on a 16x pci 1.1 micro atx board. I did a 3d mark test and got same results as people who tested it on 16x 2.0 board. Games also play great. I was thinking about getting the 4870x2 but maybe that would push my 16x pci 1.1 off the threshold. But seeing how tomshardware did tests and a 16x was pretty much identical to 8x even on a 9800gx2 then even the 4870x2 probably wont be bottlenecked by it.
Take a look at Tom's PCIe scaling review.
Specificaly the 9800GX2 tests as it requires more bandwith than a 48x0.
As 8x PCIe 2.0 has the same bandwith as 16x PCIe 1.1, you will not notice any performance drops.