PowerMac G5 Fans

Haven't seen any takeapart photos, but I can tell you where they are:

There are two in front of the processors (removeable to get to the RAM), two behind them, I believe two little ones hiding down in the power supply in the base, one beside the speaker in the front of the PCI zone, one in the middle of the drive zone at top, and a blower hiding behind that one that cools the underside of the motherboard (it looks like a funny lump of plastic). I think single processor machines didn't have two of the processor fans, so only 7 total.

That's for the earlier design, however, and I'm not positive there weren't changes made to later models (with liquid cooling, or the dual core ones).