Some measurements (taken with a kill-a-watt)
setup: idle/load
Chenming ATX-601AE 330W, P4/2.53 GHz/533, Radeon 9800Pro, 1GB RAM : 139 W/183 W (+44)
Aria 300W, Athlon XP 1800+/266, FX5200,2xPVR250: 101 W/137 W (+36)
Chenming ATX-601AW 350W, Athlon XP 2500@3200+, 333 FSB, Ti4200 108W/166W...