Can We Trust the 80 Plus Certification?
By Gabriel Torres on November 10, 2010


Introduction

The 80 Plus certification was an important step to change the scenario from the power supply industry: now the savvy consumer knows that he or she should buy a power supply with at least 80% efficiency. New certification levels (Bronze, Silver, Gold, and Platinum) raised the bar even more. But maybe it is time for a change on the 80 Plus certification methodology. Let’s see why.

For a background on efficiency and the 80 Plus certification, please read our tutorial Understanding the 80 Plus Certification.

The main flaw with the methodology used on the 80 Plus certification process is room temperature. Ecos Consulting, the company behind 80 Plus, tests power supplies at a room temperature of only 23° C (73.4° F).

We always wondered why they chose this value, because in engineering the standard room temperature for data collection is 25° C (77° F). Not that collecting data at 25° C instead of 23° C would make a big difference on the overall picture, but we always wonder why this value.

Our conspiracy minds keep thinking that this could be done to help manufacturers to achieve the 80 Plus certification on power supplies that wouldn’t be able to get the certification if they set temperature at a higher value, because the lower the temperature, the higher efficiency is. So when they were trying to market the idea of the 80 Plus certification and getting customers, this lower temperature probably helped them to please their first customers.

The problem is that unless you have a very low-power PC, temperature inside the computer case is never that low, especially if you have a gaming-grade machine.

In our reviews we test power supplies with a room temperature between 45° C and 50° C (between 113° F and 122° F), because we like to test power supplies under the worst case scenario and not under the best scenario like Ecos Consulting does.

The reason we complain so much about temperature comes to the fact that all semiconductors have an effect called de-rating. Their ability to deliver current (and thus, power) drops with temperature. To illustrate this phenomenon, consider the specifications of the SPP20N60C3 MOSFET, one of the most widely used transistors in PC power supplies. Its current limit at 25° C (77° F) is of 20.7 A, but at 100° C (212° F) the maximum current this transistor can deliver drops to 13.1 A, a huge 37% drop. The resistance of FET/MOSFET transistors, a parameter called RDS(on), increases with temperature, meaning that transistors consume more for its own operation when temperature increases, reducing efficiency. Other parameters change with temperature as well.

Is there anything wrong of using a lower temperature to test power supplies? No. It is just our personal preference to test power supplies at real-world temperatures.

The “problem” is that during our reviews we’ve seen several power supplies that received a certain 80 Plus certification not being able to achieve the same efficiency level at high temperatures. For example, some power supplies labeled as “80 Plus Silver” would need to be labeled as “80 Plus Bronze” if they tested the unit at a higher temperature range. And we’ve seen some power supplies that wouldn’t be even able to get the standard 80 Plus certification. So far we've seen only two power supply companies labeling a power supply with an 80 Plus certification level inferior from the one they got because of this phenomenon: Corsair and Thermaltake.

Thus consumers must be advised that the 80 Plus certification is achieved at a “lab environment” temperature and not at a real-world temperature, and power supplies may not achieve the advertised efficiency at high temperatures. It is our opinion that Ecos Consulting should revamp their certification program and start testing power supplies at real-world temperatures. A short-term solution would be the power supply manufacturer guaranteeing that their products can achieve the 80 Plus certification at a higher temperature, just like some manufacturers advertise that their power supplies can deliver their labeled wattage at a higher temperatures like 40° C, 45° C or 50° C (104° F, 113° F or 122° F).

Another potential problem with the 80 Plus certification is that they don't re-test rebranded power supplies. We will explore this subject in the next page.

Rebranded Power Supplies Arenít Retested

While there are several PC power supply brands on the market, there are only a few real manufacturers (also known as OEM, Original Equipment Manufacturer). Companies willing to have their own line of power supplies may use several different paths to achieve that. The most expensive way is to hire the OEM to manufacture an exclusive product, a power supply model that no other brand will have access to. And the most inexpensive way is to get a stock power supply from the OEM and simply add a different label and box, and this power supply may be sold by the OEM to other companies as well (and we end up with two or more identical power supplies being sold by different companies). This last option is what we are calling a “rebranded” power supply.

Ecos Consulting offers a big discount when a company wants to get an 80 Plus certification for a rebranded power supply (instead of paying full price, they pay only 20% of the cost). They can reduce the price so much because they simply don’t test the new power supply. Since the power supply submitted for certification is a clone of another power supply already tested, and since identical power supplies will get the same results, Ecos Consulting simply doesn’t retest rebranded power supplies. So the discounted certification fee is in fact a fee for allowing the company to use the 80 Plus logo on the product and associated promotional material, and to generate a “new” test report that is an identical copy of the report of the original power supply, changing the product and company names, and adding a picture of the rebranded power supply.

For a real example, consider the High Power HP-600-G14S, which is the original model for the OCZ ModXStream Pro 600 W, NesteQ E2CS X-Strike (XS-600), Xilence XP600, Suza TD-6002A, and GPPower Target Power TP-600. By clicking on these links you will see that all these reports are identical, as all these power supplies are identical.

One trick Ecos Consulting explained us lies in the “ECOS ID #” field of the report. You will note that all these six reports use the same ID number (636). The reports that have a “.1” after this number indicate a clone power supply, while the number without this marking indicates the original power supply. This is, in fact, a powerful trick to discover the real manufacturer of a power supply and all power supplies that are “clone” of a given unit.

According to Ecos Consulting, this is done in order to keep the 80 Plus certification costs low, allowing more companies to get the 80 Plus certification. Also, the OEM most deliver an affidavit saying that both power supplies are internally identical, and the clone power supply must be sold with the same wattage as the original power supply. Of course this procedure immediately raises the eyebrows of people that like a good conspiracy theory, as some people think that brands can fool Ecos Consulting by sending power supplies that are not identical to the model they are claiming to be the original one. We really don’t know if this happens or not, but we think it is very unlikely, since they have to sign the affidavit, which is more than enough for a massive law suit.

Because cloned units are not actually tested, some brands think that, just because they got a unit that is a clone of another power supply with 80 Plus certification, they can use the 80 Plus logo on the power supply and related promotional material for free. This is not the case. Even though the rebranded power supply isn’t actually tested, a licensing fee must be paid to Ecos Consulting (and the affidavit delivered) in order to allow the company to legally use the 80 Plus logo. We’ve seen several power supplies on the market using illegal 80 Plus logo and claims, as we exposed in our Power Supplies with Fake 80 Plus Badges tutorial.

Originally at http://www.hardwaresecrets.com/article/Can-We-Trust-the-80-Plus-Certification/856


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