From the front page of XLR8YourMac, a reader report: -- *(PC) VGA GeForce 8800 GT SC works in both old and new mac pro in Windows There are some specialties about my setup though, as I simply swapped the hard drives between the old and new Mac Pro, the new Mac Pro now runs the regular 9B18 build of Mac OS X 10.5.1, whereas the old Mac Pro runs the newer 9C16 Build. Hope this info is useful to anybody Cheers, Oliver" -------- I couldn't find a follow-up to the bit about the "PC VGA 8800 GT SC," which surprised me. I don't know if this means anything to anyone.. to me, VGA just means Video Graphics Array.. as in, not DVI. I dunno what the SC is about. Don't know of any card manufacturers with that name, and I don't remember there being an "8800 GT SC" model, but if that's helpful to someone then... well, good, I guess. Check out the front page www.xlr8yourmac.com and see for yourself.... would be best not to ask me the questions since I don't know the answers =-) Incidentally, he also said the new Mac Pros run Tiger, at least 10.4.11, just fine. I know some people were asking about that and don't know if it's been answered. Sorry if this is like, a reposting. Hopefully at least of some interest.