depending on your system configuration: for PC application (non OC purpose) 1. even the CPU (single) up to P4 2.8GHz and with all heavy loading components such as VGA card, sound card, CD_RW, SCSI HD*3...., the maximum power will be around 150W, but the peak power should up to 250W especially in ini...

Hello Leo V:
The reactive power which sustains the electromagnetic field we could not feel it without equipment, I'm not sure the power meter Mike used could measure apparent power or power factor.

The real efficiency of a power supply should be " Power factor * internal efficiency" Power factor (PF) was the factor that how we utilize the power from wall (or we say power plant) PF=working power/apparent power working power: the useful power we get from AC input appaarent power: the power provi...

Sorry to make the confuse, please refer to following explain: 1. The reason why most of PSU manufacturer just put 65% efficiency on their specification just to meet the minimum requirement of Intel power supply design guide http://www.formfactors.org/ 2. Normally the efficiency will be present as mi...