Unfortunately, the x16 PCI express slot from my motherboard got damaged. I decided to stick the card in the 8x slot instead so I could use my computer while I gather the money to upgrade my system.
My question is, Is there any significant difference between using a 16x capable card in the 8x slot instead of the proper one (16x, which in my case is damaged)?
My card is a XFX GTX 260 Black Edition and my motherboard is a Gigabyte GA-EP45C-DS3R, which has a x16 PCI Express slot.
Well, graphics cards are routinely run on 8x speed when SLI is in use - there will likely be a small performance penalty, but I wouldn't think its huge - else SLI wouldn't be worth it.
Its a bit apples and oranges but with a different (and I believe newer) graphics card - The AMD Radion HD 7970, Anandtech showed very little practical difference between x4, x8 and x16 in PCIe 3.0 (Yes, its a newer version of PCIe as well. Finding these benchmarks is hard)- since PCI-e 2.0 is half the speed look at the x4 graph for x8, and x8 for x16 . While yours is nvidia, Its a lot older and would need less bandwidth.
I'd also suggest doing a benchmark with some tool that compares it against other similar systems and getting a definitive answer. I'm guessing it should work acceptably under most workloads. Considering the scenario, it does seem worth doing.
Very few cards today can in theory exceed the x8 3.0 capabilities. In the 260's case, there is no practical difference even if you specifically run tests designed to be able to exceed the specs. So in short, you're fine.
A scenario where things would go bad is if there will be significant driver problems with PCI-E bus bandwidth management, but that's in no way a hardware limitation.
