I installed the BFG GeForce 9800 GX2 in our "early 2008" Mac Pro 3.2GHz this morning. It requires two power feeds - one 6 pin and one 8 pin. I used the 6 pin to 8 pin adapter that came with the card to plug into the 8 pin connector. If the green lights come on, you have adequate power. If red lights come on, you are in trouble. I had green lights. Yay. I booted Vista 64 and installed the latest drivers from nVIDIA. It runs Windows 3D Games faster than any Windows PC compatible card I've tried (including the GeForce 8800 GTX OC and Radeon 3870 X2 OC). Crysis: 47 fps at 1280x800 High 59 fps at 1920x1200 Medium Unreal Tournament III: Suspense Flyby at 1920x1200 Best Settings = 154 fps Prey: Prey Demo000 at 1920x1200 High (8X aniso, shadows on) = 210 fps Of course, it does not boot OS X. And it draws too many watts to run with any other card but the Radeon 2600 XT. In that scenario, you would boot with the Radeon to run Mac OS X and boot the GeForce to run Windows. But the fans on the GeForce will probably be running full blast when you are running Mac OS X. We'll let you know since we will try that next.