There is an article in next month's (Feb 2009) issue of Australian PC User Magazine which compares the real power and VA consumption of several ATX PSUs under various load conditions.
Some PSUs appear to incorporate APFC while others do not.
A Huntkey 80Master 700W PSU consumes 100W and 114VA when idling in WinXP desktop mode. However, in standby (S3) mode, with power applied to system RAM, the figures are 5W and 44.5VA. In the "off" state the numbers are 3.3W and 43.4VA.
The other PSUs also have similar results for the standby and off states.
Why are the VA figures so high?
- Franc Zabkar