So, what exactly is stopping us from using the newer cards in our Mac Pros? From what I can tell from a general search on the subject, the problem stems from the power draw of the new cards versus the old ones, with exception to the Radeon 4870 which is universal. I've installed an FSP Booster X5 450w power supply in the empty CD/DVD bay in my Mac Pro in anticipation of a new videocard, whether for Mac or PC side. If I simply dedicate that power supply to a card like, say, the Quadro 4800 or the GTX 285, wouldn't there be no problem at all? Or is the problem not with the hardware aspects of the 2006 Mac Pros but with the software/drivers for the cards? I know we don't have PCI Express 2.0 but aren't the cards supposed to throttle down a bit and still work? Heck, I'd rather have that then stick with the Radeon 3870 I've got right now. I just don't get why I can put in a big card like a Geforce 295 in my Mac Pro but not have it work for both OSX and Windows. I'm a creative professional so I want something fast for Autodesk Maya and other 3D software like it and the Radeon 3870 just isn't cutting it even using Windows XP x64 with 16gb of RAM, so I'm looking for a new video card to support that and the best is either the nVidia 4800 or the new ATI FirePro V8750 and, since Snow Leopard is out, I'd like to take advantage of OpenCL on the Mac side, but the Mac Quadro 4800 apparently doesn't work for my 2007 Mac Pro. What's the real technical deal here guys?