Hello, just bought a XFX Radeon 5870 + 2 additional 6-pin cables (from adaptare.de). No flash! OS 10.6.7, MacPro 8-core 2.26 Just put in the card after installing the updated drivers (unzipped, backupped the old ATI-data and replaced by the new). Then I booted up the machine by having one display at the old GT120 (Slot1) and one display at the ATI (Slot 3). The system profiler said (2 VGAs), that KEXT @ATI could not be loaded. After installing the drivers again I rebooted the machine, and wow, I had 2 working screens with the 2 VGAs. But the performance was very low (SC2 with 30-50FPS). Geekbench told me a lower value than with a benchmarked 4870. Then tried to put the ATI in slot 1 and take the GT120 out. No bootscreen, no OS screen. Then put the GT120 in Slot 3 and now only the GT120 is making pictures. The ATI still is not working. What to do now for making me happy? btw: The ATI is definitely louder than the stock GT120. The noise level seems to be statical (not changing).