EarthWatts is a series of power supplies from Antec with a Spartan look and relatively low cost, but able to deliver 80% efficiency and nominal power labeled at 50° C, also featuring active PFC and two video card connectors for your SLI or CrossFire setup. Let’s take an in-depth look inside the 500 W model and see if it can really deliver its labeled power.

On Figures 1 and 2 you have an overall look of EarthWatts 500 W. Its lack of any fancy finishing makes this power supply to resemble low-end “generic” models, but don’t let this fool you. This power supply is in fact a terrific product, as you will see during our review.

By the way, this is the power supply that comes with Antec Sonata III 500 case.

Antec EarthWatts 500 WFigure 1: Antec EarthWatts 500 W power supply.

Antec EarthWatts 500 WFigure 2: Antec EarthWatts 500 W power supply.

Even though it uses the traditional ATX layout with an 80 mm fan on its back it has a big mesh on its front side, improving airflow inside the power supply.

It features active PFC, a standard feature for high-end power supplies (you can see this by the absence of a 110/220 V switch, which isn’t present on power supplies with this feature). This feature provides a better usage of the power grid and allows this power supply to comply with the European law, making Antec able to sell it in that continent (you can read more about PFC on our Power Supply Tutorial).

Antec says this power supply has a minimum 80% efficiency. The higher the efficiency the better – an 80% efficiency means that 80% of the power pulled from the power grid will be converted in power on the power supply outputs and only 20% will be wasted. This translates into less consumption from the power grid (as less power needs to be pulled in order to generate the same amount of power on its outputs), meaning lower electricity bills – compare to less than 70% on regular power supplies.

And, as mentioned, this power supply is labeled at 50° C, so Antec guarantees that you will be able to extract 500 W from this power supply in the real world. Of course we will test this to see if it’s true.

This power supply comes with six peripheral power cables: two auxiliary power cables for video cards with 6-pin connectors, one cable containing three standard peripheral power connectors and one floppy disk drive power connector, one cable containing three standard peripheral connectors and two cables containing two SATA power connectors each.

We think that the number of connectors is more than perfect for the average user. High-end users will probably need more than four SATA connectors, but such users would buy a different kind of power supply anyway.

All the wires coming out from this power supply are 18 AWG, which is perfect for a power supply on this power range.

On the aesthetic side this power supply doesn’t have a nylon sleeving protecting all its wires, just the main motherboard wires.

Even though Antec paid to have its own UL number, this power supply is really manufactured by Seasonic.


Gabriel Torres is a Brazilian best-selling ICT expert, with 24 books published. He started his online career in 1996, when he launched Clube do Hardware, which is one of the oldest and largest websites about technology in Brazil. He created Hardware Secrets in 1999 to expand his knowledge outside his home country.