On Figure 17 you can see this power supply label containing all its power specs.

click to enlarge
Figure 17: Power supply label.

As you can see this power supply has four virtual +12 V rails. These rails are distributed like this:

• +12V1 (yellow with black stripe wire): EPS12V and ATX12V connectors.
• +12V2 (solid yellow wire): Peripheral and SATA power connectors.
• +12V3 (yellow with blue stripe wire): Main motherboard cable, one of the 6/8-pin video card auxiliary power connectors that is permanently attached to the power supply and one of the 6-pin video card auxiliary power connectors that is available on the modular cabling system.
• +12V4 (yellow with green stripe wire): one of the 6/8-pin video card auxiliary power connectors that is permanently attached to the power supply and one of the 6-pin video card auxiliary power connectors that is available on the modular cabling system.

We think this power distribution is ok, but we think that the main motherboard cable should be on +12V2 and not on +12V3.

Let’s now see if this power supply can really deliver 850 W of power.