TweakTown posted a review on the Seasonic S12D-850 850W Power Supply

Seasonic's S12D 850 power supply is compatible with ATX 2.2 spec
standard and supports the 24 pin ATX power connector by default. Seasonic rates the the +3.3V and +5V rails for 24 Amps and 30 Amps respectively, for a total combined output of 150W. There are two +12V lines, each can output 70 Amps for a combined output of 840W.

Seasonic S12D-850 850W Power Supply Review