StarTech.com WattSmart 650 W Power Supply Review

Power Distribution

This power supply has the following specs:

• +3.3 V: 24 A
• +5 V: 30 A
• +12V1: 18 A
• +12V2: 18 A
• +12V3: 18 A
• +12V4: 18 A
• -12 V: 0.5 A
• +5VSB: 3 A

As you can see this power supply has four virtual rails. Inside the power supply these rails are connected to the same place but each one uses an independent over current protection (OCP) circuit, usually set at a value a little bit higher than what is printed on the label.

This power supply +12V virtual rails are distributed like this:

• +12V1 (yellow with black stripe wire): ATX12V and EPS12V connectors.
• +12V2 (solid yellow wire): PCI Express auxiliary connector.
• +12V3 (yellow with blue stripe wire): PCI Express auxiliary connector.
• +12V4 (yellow with green stripe wire): Main motherboard cable and all peripheral cables.

We think this distribution is simply perfect, as the cables that really demand power (video cards and CPU – i.e., EPS12V/ATX12V) are independent and aren’t shared with the main motherboard cable or with any peripheral cable.

Now let’s see if this power supply can really deliver 650 W of power.