2.0x16 versus 3.0x16 PCI slots ?

[drknife]

Will it make a difference in hash speeds having a motherboard with 2.0 x16 PCI slots using 3.0 x16 capable video cards?

I have not been able to find any mention of this in any of the rig building guides or elsewhere.

[JoseSan]

Absolutely not. PCI-E bandwidth is not an issue for any kind of mining. You can use a single-channel PCI-E 1.0 slot if you need to.