The 80 Plus certification is conducted by an independent laboratory. Manufacturers willing to get their products certified need to send their samples and pay for them to test the units. This fee also allows them to use the 80 Plus logo if the units pass the certification process.

Like us, they only test one sample from each product. Manufacturers are advised to send at least two samples to their lab, but the extra samples are used only if the first sample fails.

It is important to take a closer look on how they test power supplies. It is very similar to the tests we do while reviewing power supplies – i.e. plug the power supply to a given load, measure how much power the power supply is pulling from the wall and voilá, we have the efficiency number – but with some important differences.

The good:

• 1. They use testing equipment with better precision. The good news is that we are moving to a wattmeter with 0.2% precision, while their methodology says their wattmeter has a precision of at least 0.5%.
• 2. Although their methodology paper says that can test power supplies under 115 V or 230 V, they usually test power supplies at 115 V, so numbers won’t be inflated by the use of a 230 V power grid.
• 3. To be certified power supplies must present a power factor (PF) of at least 0.90 (click here to understand what this is). At this moment we do not include this test on our reviews, but we will add it in the near future.

The bad:

• 1. Their tests are conducted inside a thermal chamber with a constant temperature of 23º C (73.4º F) ±5%. This is ridiculous as no computer in the world works internally at such low temperature. The problem is that as temperature increases power supplies start consuming more from the power grid in order to deliver the same amount of power on their outputs, so efficiency typically decreases with temperature. Our tests here on Hardware Secrets are conducted with a temperature between 45º C and 50º C (113º F and 122º F) inside our thermal chamber, as we want to measure power supplies under real-world conditions.
• 2. Power supplies are tested only under three loads: 20%, 50% and 100% (called “light”, “typical” and “full”, respectively). At one hand the use of these three loads is enough for having an overall idea of the power supply efficiency. On the other hand, for a more precise measurement it is our opinion that they needed to do tests under several different loads, especially when they are charging for doing so. In our tests we test power supplies under five different loads: 20%, 40%, 60%, 80% and 100%.
• 3. They don’t disclose the exact equipments (e.g. manufacturers and models) they use on their testing.

Let’s see now the differences between the existing 80 Plus certifications.