So I got hold of a good, working ATI Radeon X800 Pro with 256MB of VRAM, to put in my G4/1.467 upgraded Digital Audio. (Scored about 15750 on the Openmark test, don't remember the exact number.) The CPU is an OWC upgrade rated up to 1.5 GHz, but based on the multiple of the bus speed on the G4DA (this was originally 667MHz), 1.467 was the top usable rated speed. The problem I was having for a while was that some apps, mostly TenFourFox, were frequently crashing on me. I wasn't sure why but I explored a few avenues, and at one point I decided to *open* the side of the computer and run it that way. The crashes seemed to stop! Well, I figured at that point it might be heat. I shut down, moved the two PCI cards I had (a USB 2.0 card and the original SCSI card, which in reality I can probably remove) to the two slots farthest from the video card which was belching out a lot of heat. I rebooted. It worked for a while without any slowdown or crashing. Then I decided to close the door and really test it. Stable, smooth, fast. Before moving the PCI cards I could actually feel the slowdown, the beachball and know a crash was coming. I'm actually TRYING to crash it with activity now and I can't. So here's at least one data point -- if you have a PCI-based Power Mac, and you have a badass video card, if you have random freezes and application crashes.... move all the PCI cards away from the graphics card and let it breathe! It may not always work, but it's worth trying.