OCZ Fatal1ty 750 W Power Supply Review

Power Distribution

In Figure 15, you can see the power supply label containing all the power specs.

Figure 15: Power supply label.

According to the label this unit has four +12 V rails. Inside the power supply the unit has four “shunts” (current sensors – see Figure 16) and although the monitoring integrated circuit supports only two +12 V OCP channels, it uses two voltage comparators to “expand” these inputs. So this unit really has over current protection enabled and, therefore, four +12 V rails.

Figure 16: Four “shunts” (current sensors).

The four rails are distributed like this:

• +12V1 (solid yellow wires): Main motherboard cable.
• +12V2 (yellow/red wires): Half of the ATX12V/EPS12V connector.
• +12V3 (yellow/green wires): Half of the ATX12V/EPS12V connector, half of the modular connectors (two for video cards and two for SATA/peripheral).
• +12V4 (yellow/black wires): EPS12V connector, half of the modular connectors (two for video cards and two for SATA/peripheral).

We think this is not a good distribution, especially because the rails are not easily identified outside the unit. Therefore, you may end up having your CPU and your video card running on the same rail, and even two video cards and the CPU running on the same rail.

Now let’s see if this power supply can really deliver 750 W.