I'm looking into buying a new Asrock Z77 Extreme 6 motherboard that I will pair with an i5 3570K chip & X2 Gigabyte GTX 560Ti Super Overclocked cards in 2 way SLI. My question is; are the 2 PCI express 3.0 lanes far enough away from each other to not have my cards 1 on top of the other? From the image on Newegg I can't make a judgement & would like to ask for your help.
First, unless you purchase (a) new GPU(s) the nVidia GTX 500 series is PCIe 2.0.
The ASRock Z77 Extreme6 is spaced for triple slot GPUs so you'll have good airflow to each GPU. My preference is the ASUS Sabertooth Z77 or ASUS P8Z77-V PRO/P8Z77-V or P8Z77-V PRO Thunderbolt (if you'll ever use or want Thunderbolt).
the difference between pci-e 2.0 and 3.0 is like 1-2 fps, and thats only applies to pci-3.0 cards. GPU's this age havent fully utilized the full speed of a pci-e 2.0 lane. heck technically a gtx 680 in a 4x slot still runs at like 94% speed according to a slightly old test i cant remember which page it was on. Its going to be awhile till gpus fully utilize a pci-e 2.0 slot+