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Power supplies perform an essential function for a computer; they provide stable power for all of the components inside the system. Packed with features and specifications, reading the product description for one is nearly a chore. For instance, have you ever wondered what 80 PLUS® denotes? If you’re a system builder, it’s time to pay attention—class is in session.

When buying a computer power supply, most system builders usually estimate the total power draw of the hardware in watts and then choose a power supply that can supply at least that much power. However, relying simply on the wattage rating is often not satisfactory for some builds. This is where 80Plus and those different levels of certification come in.

Initiated by Ecos Consulting (Now Ecova®) in 2004, 80 PLUS is a voluntary certification program that tests computer power supply efficiency. With the intention to promote environmental friendliness and energy efficiency, 80 PLUS certification is given to power supply models that meet an energy efficiency minimum. But what does energy efficiency mean and does it really matter?

In the context of power supplies, energy efficiency is the amount of power provided by the power supply divided by the amount of power it draws from the power outlet and expressed in a percentage. It boils down to the amount of power provided versus the amount of power it draws. For example, if a power supply draws 100 watts and provides 80 watts of power, it has a energy efficiency of 80%.

However, power supplies do not maintain static energy efficiency levels. In actuality, energy efficiency varies depending on how much load is being put on the power supply. Continuing with our imaginary 100 watt power supply above, it may be 80% efficient under 100% load but drops to 50% efficiency when at 50% load.

For a manufacturer to get an 80 PLUS rating for a model of computer power supply, they must submit samples to an independent lab to test energy efficiency. In these labs, a power supply is tested for efficiency at 10%, 20%, 50%, and 100% loads. Below is a table showing the different requirements for each level of certification.

Levels of 80Plus certification for 115 V consumer-grade power supplies and their efficiency requirements

80 PLUS Certification Levels Efficiency at 10% Load Efficiency at 20% Load Efficiency at 50% Load Efficiency at 100% Load
80 PLUS 80% 80% 80%
80 PLUS Bronze 82% 85% 82%
80 PLUS Silver 85% 88% 85%
80 PLUS Gold 87% 90% 87%
80 PLUS Platinum 90% 92% 89%
80 PLUS Titanium 90% 92% 94% 90%

80Plus certification for 230 V server-grade power supplies and their efficiency requirements

80 PLUS Certification Levels Efficiency at 10% Load Efficiency at 20% Load Efficiency at 50% Load Efficiency at 100% Load
80 PLUS
80 PLUS Bronze 81% 85% 81%
80 PLUS Silver 85% 89% 85%
80 PLUS Gold 88% 92% 88%
80 PLUS Platinum 90% 94% 91%
80 PLUS Titanium 90% 94% 96% 91%

If your business operates a great number of computers or servers, using 80 PLUS certified power supplies can save money in the long run. Bronze certification seems to strike a good balance between low initial purchase cost and high performance. What are your thoughts on 80 PLUS certification and computer power supplies however? Do you pay much attention to power supply 80 PLUS ratings when shopping for a build?

Photo by itchys, taken from Flickr Creative Commons
Wallace Chu

Author Wallace Chu

A self-professed tech hipster that loves computers and music. Uses an iPhone ironically.

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