Quote from: MegaBux on September 29, 2011, 04:28:55 AM

When I measure power consumption at the wall, I read about 1050W. What does this number represent? Is it the power draw of the power supply, after which 924W are provided to the system?

Yes this is correct.

Quote

Or is it the actual consumption of the system after taking into consideration its efficiency (1050 / 88% = 1193W)?

No this is incorrect.

IF your powersupply is 88% efficient then 1050W AC at the wall means the power supply pulls in 1050W. It converts 88% of that (924W) into useful DC electricity and converts the remaining 126W into heat.

Remember though efficiency varies depending on load. Your powersupply is well matched. Generally you want load to be 60% to 80% of peak because that is where powersupply is the most efficient.