In the world of power-supply units (PSUs), the 80 PLUS program is not a new phenomenon. But its relevance--or at least the relevance of power conservation--has increased as the years have gone by.
80 PLUS was initially launched in 2004 by Ecos Consulting. It's a voluntary efficiency-certification program, with an emphasis on the "voluntary"--nobody actually forces manufacturers or brands to certify their PSUs under the 80 PLUS standards. The program got its name from the 80% minimum efficiency that a power supply needs to exhibit for its first level at 20% load, 50% load, and its full rated load, along with a power factor (PF) of at least 0.9 with full load.
The Evolution of 80 PLUS
This program has helped many users realize the importance of recognizing efficiency in power supplies, and it has also helped make active power factor correction (APFC) converters popular. Indeed, these days, most desktop PSUs feature such a converter. In 2007, Energy Star adopted the 80 PLUS program, and despite its shortcomings, it's currently the most popular efficiency-certification program.
As we mentioned, the 80 PLUS program initially required efficiencies higher than only 80% at three different load levels, along with a single PF reading, to qualify for its certification. However, as years passed and the technology in PSUs evolved (allowing for higher efficiency levels), new certification levels inevitably had to be worked into this program. Moreover, at first, non-redundant power supplies were certified exclusively with 115V input, with redundant units being certified with 230V. Later, though, a 230V certification program was introduced for PSUs used in desktop, workstation, and server applications in non-redundant configurations.
This new 230V program has proved to be not as popular as the 115V one. Basically, with 230V input, the overall efficiency difference, compared to 115V input, is around 1% to 1.5%. (Thus, the overall efficiency difference between two PSUs will remain the same if both of them are tested with 115V or with 230V.) In addition, an 80 PLUS certification program exists for 115V in PSUs used in industrial applications, with no restriction on their physical format. This program, so far, has had very few takers.
Before we proceed further into the details on the 80 PLUS levels, we should explain what "efficiency" means. Let's assume that our power supply delivers 300W to the system but actually draws 375W from the wall. This means that its efficiency is 375W/300W, which equals 0.8 or 80%. Those additional 75W produce nothing but heat.
The more efficient a PSU is, the less heat it produces internally, and of course the lower its energy consumption. The amount of heat produced is key, because it affects the performance of the PSU and the lifetime of all of its parts inside. On top of that, the higher the thermal load, the tougher the job for the PSU's cooling system. High-efficiency PSUs, then, have a head start compared to lower-efficiency units when it comes to reliability and performance, all else being equal. They can run quieter, as well.
The Current 80 PLUS Levels
115 Volts Input
|80 PLUS Certification||115V Internal Non-Redundant||115V Industrial|
|% of Rated Load||10%||20%||50%||100%||10%||25%||50%||100%|
|80 PLUS||---||80%||80%||80% / PFC .90||---|
|80 PLUS Bronze||---||82%||85% / PFC .90||82%||---|
|80 PLUS Silver||---||85%||88% / PFC .90||85%||80%||85% / PFC .90||88%||85%|
|80 PLUS Gold||---||87%||90% / PFC .90||87%||82%||87% / PFC .90||90%||87%|
|80 PLUS Platinum||---||90%||92% / PFC .95||89%||85%||90% / PFC .95||92%||90%|
|80 PLUS Titanium||90%||92% / PFC .95||94%||90%||---|
As consumers, we mostly care about the "115V Internal Non-Redundant" levels. There are six 80 PLUS levels in total for non-redundant (desktop) PSUs:
- 80 PLUS
- 80 PLUS Bronze
- 80 PLUS Silver
- 80 PLUS Gold
- 80 PLUS Platinum
- 80 PLUS Titanium
Currently, you'll hardly find any PSU on the market with the plain-old 80 PLUS certification, and usually the best efficiency-per-dollar score is delivered by Gold units. The 80 PLUS Silver certification hasn't been very popular, because most manufacturers prefer to flog either the Bronze (budget-minded) or Gold (premium-minded) levels. Finally, the prices of Platinum-certified PSUs fell significantly once Titanium units made their appearance. (Of course, the latter tend to be pricey at a given level of specs.)
Indeed, the introduction of the 80 PLUS Titanium standard brought a fourth measurement into the certification mixture: efficiency at 10% rated load. Also, with Titanium, PF needs to be at least 0.95 at a lower load level (20% of the PSU's max-rated capacity). Note that the lower the load in a PSU, the tougher it is for its APFC converter to keep the power factor high.
In our opinion, the Titanium level is the most significant of the 80 PLUS certifications, because it's the first to take into account the efficiency under such a light load level. To this point, manufacturers easily could tune their PSUs to perform better with 20% load and not weigh efficiency at lighter loads so heavily. However, given the power consumption levels of modern GPUs and CPUs (especially under light loads, thanks to their advanced energy-saving features), it is imperative for a power supply to offer high efficiency at load levels that are only a fraction of its maximum rated capacity.
230 Volts Input
|80 PLUS Certification||230V EU Internal Non-Redundant||230V Internal Redundant|
|% of Rated Load||10%||20%||50%||100%||10%||20%||50%||100%|
|80 PLUS||---||82%||85% / PFC .90||82%||---|
|80 PLUS Bronze||---||85%||88% / PFC .90||85%||---||81%||85% / PFC .90||81%|
|80 PLUS Silver||---||87%||90% / PFC .90||87%||---||85%||89% / PFC .90||85%|
|80 PLUS Gold||---||90%||92% / PFC .90||89%||---||88%||92% / PFC .90||88%|
|80 PLUS Platinum||---||92%||94% / PFC .90||90%||---||90%||94% / PFC .95||91%|
|80 PLUS Titanium||90%||94% / PFC .95||96%||94%||90%||94% / PFC .95||96%||91%|
As with the 115V certifications, there are six levels for the 230V input 80 PLUS certifications--for non-redundant PSUs. For redundant PSUs, which are usually used in data-center applications, there are five levels in total. (The base level for those is 80 PLUS Bronze.)
The 80 PLUS Titanium 230V EU requirement at 10% load is the same as for the 80 PLUS Titanium 115V. As expected, the requirements at the next three load levels are higher. At this writing, we know of only one PSU that meets the 80 PLUS Titanium 230V EU requirements--and that model features a custom form factor, so it's not compatible with ATX chassis.
80 PLUS Shortcomings
Nothing is ever perfect, and the 80 PLUS program is no different. It also has its deficiencies, which we would break down accordingly:
- 80 PLUS requires only a small number of measurements to classify a PSU into one of its categories.
- The methodology allows for manufacturers to submit "golden" samples (that is, hand-picked models that perform ideally).
- Measurements are conducted at a very low ambient temperature (23C, ±5C).
- The process doesn’t measure standby power consumption ("vampire power"). This measurement is essential in the European market, where all PSUs should comply with the ErP Lot 6 and ErP Lot 3 directives.
- The testing doesn’t take into account the 5VSB rail’s efficiency.
- The standard makes no clear mention of testing equipment.
- 80 PLUS doesn’t deal effectively with the problem of fake efficiency badges.
Should you want to know more about our perceived shortcomings in 80 PLUS, you can take a look at our earlier explainer on 80 PLUS, Is 80 PLUS Broken? How To Make It A More Trustworthy Certification.
Disclaimer: Aris Mpitziopoulos is Tom's Hardware's PSU reviewer. He is also the Chief Testing Engineer of Cybenetics, and developed the Cybenetics certification methodologies apart from his role on Tom's Hardware. Neither Tom's Hardware nor its parent company, Purch Media, is financially involved with Cybenetics. Aris does not perform the actual certifications for Cybenetics.