Soleron on 02 November 2009
1. Yes, it should work. Whether it actually does or not is another question. I thought USB3 had been pushed back and the first devices will be in 2011? I know Intel isn't putting it in their chipsets until 2011, and no vendor will pick it up until they have it.
2. http://www.techpowerup.com/reviews/AMD/HD_5870_PCI-Express_Scaling/
I doubt it would make any difference to your 4870 in any case. As you can see from my link, you would get 99% of the performance using PCIe 2.0 x8 for a 5870. However, if that's v1.0 x8 then that's just like v2.0 x4 and would be 95% of the performance for a single 5870. So you wouldn't see an impact if it's PCIe 2.0, but you would for 1.0.
