I'm thinking of upgrading my GPU to a 7870 from my 6870. Right now I'm running a Phenom II x4 955 with 4GB RAM at 1333 mhz. I'm just wondering if I might see a bottleneck with this CPU/GPU combo and whether I need to consider upgrading the CPU as well. Any advice would be greatly appreciated!
The 955 won't bottleneck the 7870. I built a computer for my mom based on 955BE clocked @ 4.0Ghz on a 990FXA-UD3 board with a gigabyte 2GB 7850 and ran BF3 like a champ. I wanted to see what my moms setup would do, that's why I installed BF3 on her computer. I would actually up your ram to 8GB at 1600mhz.
Cool, that's what I was wondering. I don't overclock (not enough disposable income to afford mistakes) but I've been playing BF3 among other things and I'm hoping a bump up to a 7870 will improve framerates a bit. I'll see about upgrading the RAM too.
I have a Phenom II X6 1605 with a 7870, and my CPU occasionally does bottleneck my system, depending on the game. While overall CPU usage is never a problem, poorly-optimized games (Planetside 2, for instance) will max one thread of a Phenom, slowing everything down. On the other hand, it's never made anything unplayable; I still max Bioshock Infinite no problem. Phenoms are decent for overclocking too, so that could be an alternative to upgrading, temporarily at least.
Right now there aren't any limiting factors when using PCIe 3.0 card in a 2.0 lane. The cards out can't fully saturate a PCIe 2.0 lane let alone a 3.0 lane. The only difference is in speed. PCIe 2.0x16 = PCIe 3.0x8.