"The Zeus 850W power supply supports ATX12V v2.2/EPS12V and is rated
for a combined, continuous output power of 850 watts at up to 50°C ambient
air temperature (internal case air temperature). This is an important
feature and one many generic power supplies don't have. Many less expensive
power supplies rate their output capacity based on 25°C, which is not
realistic. If SilverStone rated the Zeus 850W this way it would be
advertised as a 1,050W power supply."