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

click to enlarge
Figure 17: Power supply label.

This power supply has four virtual rails, distributed like this:

• +12V1 (solid yellow wire): Main motherboard cable, peripheral power plugs and SATA power plugs.
• +12V2 (yellow with black stripe wire): ATX12V and EPS12V connectors.
• +12V3 (yellow with blue stripe wire): One of the video card auxiliary power cables that come from inside the power supply and one of the video card auxiliary power connectors from the modular cabling system.
• +12V4 (yellow with green stripe wire): One of the video card auxiliary power cables that come from inside the power supply and one of the video card auxiliary power connectors from the modular cabling system.

This unit has its rails well distributed.

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