We are starting our first project, but it appears there is a GPU problem on one of our older dual quad cores with an ATI 4870 graphics card. Clips in FCPX rotate through the color spectrum and soften during playback on timeline or clip view. Play the same clip in QT, or on my quad core iMac inside X and it plays correctly. Exported clips play correctly on the desktop too.
8-Core 3.0 Intel Mac Pro, Dual 2 gig G5, AJA Kona SD, AJA Kona 2, Huge Systems Array UL3D, AJA Io HD, 17" MBP, Matrox MXO2 with MAX - Cinema Displays I have a 22" that I paid 4k for still working. G4 with Kona SD card, and SCSI card.