It's been a while since I've opened my mac's case. I had to switch one of my cards to another and suddenly noticed that the pci-cards are pretty hot, I mean very hot! Mainly the UAD1 cards heat sinks are so hot that I can hardly touch them with fingers. I reorganized the cards so that the UAD1 cards are on top and the powercore is on the bottom. This way the powercore runs much cooler. Now I appreciate the design of the g5 powermac cause there is an extra cooler for the pci cards too.