MSI GTX 580 1.5gb PCIe 2 or MSI GTX 660 2gb PCIe3, both SLi 2 way

[Alexlowe88]

I wonder if anyone can help. I want to upgrade my existing Gigabyte GTX 460 1gb SLi. I was originally interested in the MSI GTX 660 2gb but that was before I remembered that my motherboard, xfx nforce 790i ultra SLi only has PCIe 2. I read that PCIe 3 is backward compatible. But I am worried that the performance will drop too much. I want to play Metro Last light at 1920 x 1200. If so, I may as well go for the MSI GTX 580 1.5gb which is PCIe2. The 580 is £30 more expensive. I find it difficult to buy something that is older and more expensive. But if it can give me stable and better performance while running Metro Last light at 1920 x 1200 ultra, I will go for it. If, there is no drop in performance using PCIe 3 card in PCIe 2 slots, I definitely will go for the 660. Can anyone help me onto the right track? Many thanks in advance.

 

[TheMentalist]

It will work fine, you will hardly see a difference in performance

 

[Alexlowe88]

It will work fine, you will hardly see a difference in performance

thank you very much for your help.

 

[Alexlowe88]

I am now running 2 x MSI GTX660Ti OC edition 2gb in SLI on my XFX 790i Ultra SLI motherboard. I can run Metro light at max without problem. I even managed to run Crysis 3 at 1920x1200 at high (not ultra) without stutter. However, it does take a few seconds longer to load whenever I get into new area. Apart from that, the gameplay is smooth.