do you think this is to much for a 300 psu? 2x cellie 500 oc'd@600 on abit bp6 256 meg pc100 voodoo 3 2000 agp SB 128 2 Nics 1 56k 3 4.3 hdds 1 40 hdd 5800 rpm 1 44x cdrom 1 20x10x40 cdrw 2 120mm Deltas fans 4 80mm fans and ofcourse the 2 40mm HSF
Simple answer: No, if it doesn't crash under load. I would imagine it's more important to know what the available amps are for 3.3, 5 and 12V. Not all 300W power supplies are built the same. Then compare them to the total components load including the cpu(s) for each voltage.
Depends on the 300W. My old AOpen 300W struggled with my system (5PCI cards, overclocked graphics, heavily overclocked Athlon (which draws about 2x as much as a pair of cellys as you have), hdd, dvd, cd-rw, etc, etc. My Chieftec 340W, although hardly rated much different (with 315W true combined rating (which is the important measure, and often very different to the ideal rating...many "300W" supplies are really about 150W true combined power)) copes much better.
