In place of either card, I highly recommend this one. Since you are an overclocker, this one is able to reach extreme speeds, over a 25% overclock from a reference HD5850. This allows it to surpass an HD5870.
But there is no difference between the PCI-E 2.0 and 2.1 cards. Either one will work fine.
there this thing called...Wikipedia....and it knows all.......
"PCI Express 2.1 supports a large proportion of the management, support, and troubleshooting systems planned to be fully implemented in PCI Express 3.0. However, the speed is the same as PCI Express 2.0."
thanks shadow, i just went ahead and ordered the 2.0 xfx one to save some money i probably wont get as good as an overclock as one you linked, but the few mhz difference dont think it will make a difference in games any time soon.
yes ct thanks i saw that generic answer already but i wanted it explained more clearly