In Figure 14, you can see BFG 800 W label stating all its power specs. BFG doesn’t say under which temperature their power supply is labeled (but don’t worry, we will test this).

click to enlarge
Figure 14: Power supply label.

As you can see this power supply has four virtual rails, each one rated at 20 A. These rails are distributed as following:

• +12V1: Main motherboard cable.
• +12V2: EPS12V and ATX12V cables.
• +12V3: One of the SATA cables, one of the PCI Express (video card) cables and one of the peripheral cables containing three connectors.
• +12V4: The other SATA cable, the other PCI Express (video card) cable, the other peripheral cable containing three connectors and the peripheral cable containing two connectors.

On the "Limited Edition" model the two extra PCI Express auxiliary cables are connected in parallel with the two existing video card cables, therefore on this model we have two video card power cables connected to the +12V3 rail (one light blue and the other dark blue) and another two video card power cables connected to the +12V4 rail (one light blue and the other dark blue).

We think that BFG made a terrific job on the rail balancing. Several power supplies connect the EPS12V and ATX12V cables on different rails, which doesn’t make sense as they aren’t used at the same time (maybe there is one or two extremely high-end motherboards that do, but they are the exception, not the rule).

The only problem we see is that there is no way to identify which of the SATA, PCI Express (video card) and peripheral cables are connected to which rail without opening the power supply, as there is nothing identifying them externally! This is really a shame. BFG should have labeled these cables as “1” and “2” so you could know which cables are sharing which rail.