I found a great setup by another user on this forum that almost exactly matches what I'd like to do with my own rig. The big difference is they built off a Mac Pro 2008 chassis while I'm starting with a late 2009. He notes, on this flickr page how the 2009 case has physical differences that may not support the PSU. Their 2008 setup: http://www.flickr.com/photos/36197914@N08/sets/72157616169842077/ This is the modular PSU I believe they used: http://tinyurl.com/24n8vcd They installed x2 ATI 4870 cards. I'd like to do the same thing, but with x2 ATI 5870 cards. Can anyone confirm if that is the PSU I need to install and if that particularly modular PSU will fit inside of the Mac Pro 2009 case? I know Crossfire will not work under OS X but I occasionally dual boot in Windows 7 for gaming and, much more importantly, I run dual 27" Apple LED monitors that I'd like to run independently on each card to minimize the amount of overhead for things like Adobe Creative Suite 5, FCP and 3D modeling. MANY THANKS!