Thanks Stewer, I am using a UPS (uninteruptable power supply) which monitors power drain, usage and qualitity of power. It indicates that the machine is not pulling that much load (50% in fact)The power supply is of the heavy duty type, capable of powering many more devices than I have fitted. If the CPU was pulling too much power the LCD monitor on the Thermaltake case would show an increase in heat - in fact it hardly ever changes by + or - 1 degree.