I have two Geforce GTX 680 Mac edition cards and would like to run them both on my 5,1 Mac Pro. I already have a way to power them both. Is it ok to use a riser cable to install the second card in Slot two and just have the card setting outside the case with the case open so that it doesn't block slot 3 or 4? Is there any reason that this wouldn't work or isn't advised? Thanks! Here are a couple options for cables: https://www.amazon.com/EZDIY-FAB-Ex...F8&qid=1523809133&sr=8-3&keywords=riser+cable or https://www.amazon.com/Thermaltake-...F8&qid=1523809133&sr=8-4&keywords=riser+cable Any thoughts would be greatly appreciated!