New computer: PCI 2.0 GPU work with PCI 3.0 MoBo?

I am going to buy a computer rig for Cycles off Craigslist, but the GPU it comes with is not very good for cycles. He is willing to keep his GPU (gtx 770), and reduce the price. I will just get a GTX 580 elsewhere. However, the mother board is PCI express 3.0 and the GTX 580 is 2.0. I think it will work, but will there be performance loss? I understand a PCI 3.0 is not going to make the 580 run better, or at PCI 3.0 speeds, but will it be slower compared to running the 580 on a PCI 2.0?

Here is the rig I’m looking at in case anyone is curious:
http://akroncanton.craigslist.org/sys/4195724976.html

Thanks for any help!

it will work as long as you have enough power(power supply)

edit says it comes with 1200watt, that is more than enough.

Hi holyenigma, and thanks for the quick response :slight_smile:

yes, i know it will work, but will there be performance loss?
Please read the full post

it will just run at 2.0 speeds, 3.0 is backwards compatible.
just like how a USB2 stick will run in a USB3 port.

if you dont need it right away maybe wait a bit for the Maxwell GPU’s

You think those are going to be better for cycles than 700 series? It was quite disappointing to see how the 600 and 700 series performed with cycles.
Have they announce when in 2014 they are supposed to come out?

from the roadmap it looks like early 2014(just guessing Feb or March?)

its supposed to have the unified memory architecture so if cycles takes advantage
of CUDA 6 then it should have improvements.