Your Mac pro will not boot if you have more than 80 Gigs of Ram. I had to go back down to 64 gigs of ram on my 2012 Dual Processor 3.06 Mac Pro. You will be stuck at PCI configuration. 10.8.2 doesn't work, but 10.8.1 does. Seems to affect all the mac pros that can take more than 64 gigs of Ram.