ntdreuzhawaiirrcom saturday 09 february 2008 093913 randall r schulz wrote saturday 09 february 2008 1122 philippe landau wrote randall r schulz wrote saturday 09 february 2008 1008 philippe landau wrote many power supplies efficient dont operate close full load seemed counterintuitive decided little looking around according graph page 14 power supplies hidden opportunity energy savings case much depends power supply question course go back original question mine issue whether highly overrated supply wasteful power appears randall schulz disagree looked bunch efficiency plots 80plusorg generally peak 50 rated load around 8485 low load 20 efficiency around 82 high load 100 efficiency around 80 400 watt load typical would say todays computers 800 watt power supply would draw around 470 watts would operate 85 efficiency 400 watt load 400 watt power supply would draw 500 watts efficiency 80 load 550 w power supply would draw around 488 watts efficiencyaround 82 typical efficiency curve shown site 400 watt load supplied 2000 watt power supply would draw 488 watts 20 load efficiency 82 better get power supply least twice big load even rating way greater say 4 times requirement efficiency better using power supply 75 capacity suv syndrome fails applied power supplies tue 05 aug 2008 144308 1000 opensuse power supply psu efficiency unstable system culprit