Want to verify 100% load is no problem

[CBRworm]

I just want to make sure. I built this SFF PC with a Delta 250 watt power supply. It is a P965 w/ E6600 w/ an ATI X2600XT and 2 750gb Sata drives along with all the other normal stuff (2gb ram, optical drive, fans, etc). When I am playing a game (yes you can play a game with the 2600) my kill-a-watt says I am drawing just under 300 watts from the wall. I figure with the inefficiencies that means I am probably drawing just about all the power from this 250 watt supply available. I just want to verify that long term it should be able to handle it without failing - The machine will run 24/7, but at idle the machine was only drawing just over 100 watts from the wall.

Is it a bad sign that while I am running TAT @ 100%, if I am in ATItool and run the Scan for Artifacts (puts load on video) that the system fans all slow down about 200rpm until I stop scanning? I think that is related to all the power being drawn through the motherboard (this video card has no PCI-E power connector) The voltage drop at the molex connectors is only .2 volt on the 12v line. The system fans are all connected to the MB.