Monday, November 15, 2010

Who's Who In Power Supplies: Brands, Labels, And OEMs

Did you think all power supplies were manufactured by the brand selling them? We show you what makes a good PSU and reveal who actually builds PSUs. You can actually find lots of quality, instead of just scrap metal, behind some of the budget labels.

Between gobs of reader feedback and our own data compiled over many years, we've managed to put together a fairly comprehensive list of power supply brands and manufacturers. Despite the fact that it consists of more than 150 manufacturers, though, this list still doesn't reflect the entire market, which always seems to be in a state of flux. It can, however, be used as a guide to finding the difference between a bad deal and a bargain.
Who is Who?
Let’s start by dividing the manufacturers into three large groups so we can better understand the database and how these companies are connected:
1. The OEMs (Original Equipment Manufacturers)
OEMs manage all of their production internally. They either exclusively design and manufacture their own PSUs (like Enermax) or design and manufacture their own brands, as well as manufacture PSUs designed by other companies (such as FSP, HEC, and SeaSonic). Some of them focus heavily on worldwide exports and provide a range of models, which are later sold under different labels. It's common to find otherwise-identical models marketed under many different names and labels. The industrial areas around Shenzhen, China, are the cradle of the lowest-priced PSUs sold all over the globe.
2. Designers: Without Their Own Production
The second group of companies also develops and designs their own products. However, they have to outsource either some or all of the manufacturing to other companies. One example of this is Be Quiet. Those familiar with the brand noted how Be Quiet P7 models were suddenly much better than the disappointing P6. The answer was simply a manufacturer change, from Topower to FSP. Other examples of designers include SilverStone, PC Power & Cooling, and Tagan.
3. The Labels: With or Without Any Technical Involvement
Arguably, this group could be subdivided. Some importers of foreign PSUs that resell models under their own labels have a certain influence over the quality and choice of components, while others simply bring in some very cheap products, relabel, and resell them.
This third group is the most interesting one for price-oriented customers, though also the most uncertain for quality. You're as likely to score a bargain by getting a relabeled high-quality product at a lower price as you are to be disappointed by being too tight-fisted. Some good examples of products to watch are new models from Aerocool, which are essentially the Cougar units from Compucase/HEC with a discounted price and completely restyled exterior. The same goes for Corsair, which contains slightly older (but solid) SeaSonic designs and technology.
After many tests and inspections of budget models (by us, our readers, and friendly computer stores), we would advise you to steer your piggy banks clear of the labels Rasurbo, Inter-Tech (Sinan Power, Coba), Tech Solo, LC Power, RaptoxX, Tronje, Xilence, Ultron, World Link, Q-Tec, etc. We were able to identify some of these models without looking at the UL number simply by having a look at the installed components. These were almost exclusively the simplest work of such manufacturers as Enhance, World Link, Andyson, Topower, Casing Macron, and Channel Well.
Lack of protection circuits, low efficiency, and bad build quality were major points of criticism. The lowest of the low was a European label called Hardwaremania24, targeted at OEM PCs. While still in standby mode, the PSU heated to about 176 degrees Fahrenheit, spent the next six hours billowing smoke, and finally made what might be described as a trumpeting sound before dying. The host computer was never even turned on. After analyzing the PSU, we found no protection at all save for a single slow fuse.

How do you identify a bad power supply before buying it?
  • Extremely high wattage claims at a comparatively very low price are suspicious. There are simply no decent 750 W power supplies for $50. For every product class based on performance and features, there must be a minimum price. When a product is significantly below that price, be cautious. You can get a "400 W PSU" for $20, and such fire hazards are installed in budget PCs every day by unscrupulous companies that know exactly the risk they're handing off to buyers.
  • Check the specifications. For example, if a PSU claims high performance on the 3.3 and 5 V rails while the 12 V rail numbers are low, then you know something is wrong.
  • The manufacturer does not specify any combined maximum performance, but instead only shows the maximum load for each rail separately. This is done without specifying how much real power would be available if all rails are used at the same time. Avoid PSUs without this information.
  • Be careful with juicy marketing expressions and commercial lingo: Super, Extreme, Gaming, Combat, etc. Using superlatives to describe something quite normal should arouse suspicion and have you double-check specification details.
  • Passive rather than active Power Factor Correction (PFC) leads to lower power efficiency.
  • Very few or short power connectors and cables might be an issue. A 750 W PSU usually has four PCIe connectors for graphics cards (2 x 6-pin and 2 x 6+2-pin), so think twice if a model only offers two (or at least consider your upgrade options).
  • With cheap PSUs, the quality of the cable insulation may be poor, or the cables may not be insulated at all. The power cable grommet may also be insufficiently padded.
  • Be careful if there are few or no indications of protection circuitry. If the PSU specification only says OPP (overload protection) or perhaps SCP (short circuit protection), this points towards a normal fuse. If the specification also says OVP (overvoltage protection), this probably means that it is equipped with a simple metal oxide variable resistor. These security measures by themselves are absolutely insufficient and cannot replace any kind of digital safety chip.

Unfortunately, you can't always tell at first glance whether you're dealing with a high-quality PSU or whether there's nothing but disappointment waiting behind the pleasant facade. Therefore, we decided to open up two budget PSUs representative of what you can find in many of today’s OEM PCs and illustrate the points and features you should be examining.
A First Look At the Inside: Primary Capacitor and PFC
First, look at the storage capacitors in the primary circuit. These act as buffers and help protect the PSU and computer from voltage fluctuations. The electrolyte used in them is key, because it evaporates or dries out through a combination of heat and time. As a general rule, capacitor lifetime is halved for each 10 degrees Centigrade increase in temperature over the specified normal load. Using higher-quality capacitors that can handle 105 degrees instead of 85 degrees (C) should almost double their lifetime, greatly contributing to the PSU's durability.
A PSU equipped with chokes (a kind of inductor) is a clear indicator of passive Power Factor Correction (PFC). Passive PFC plays a significant role in the efficiency of the PSU. Only active circuitry allows for factors close to the optimum value of 1, while passive components can reach 0.7 to 0.8 at best, meaning they only achieve 70% to 80% efficiency. PSUs with a passive PFC may be cheaper to buy in the short run, but poor efficiency can swallow savings over time in the form of higher electricity costs.
Protection Circuits
Even without opening the PSU, a data sheet can reveal some of the safety measures taken (or not) by manufacturers. A decent PSU should contain the following safety measures:
  • OCP (Over Current Protection): protection against power spikes
  • OVP (Over Voltage Protection)
  • OPP (Over Power Protection): overload protection, sometimes called OLP 
  • OTP (Over Temperature Protection): protection from overheating 
  • UVP (Under Voltage Protection) 
  • SCP (Short Circuit Protection) 
  • NLO (No Load Operation): this isn’t exactly protection in the same sense as the other features, but it allows the PSU to power up and function normally, even with no load.

Without this information, you have to look inside the PSU to find out what you need to know.

We found no protection at all on this unit, except for a simple fuse. Sadly, this PSU is still available on the market under a couple of different labels.
Passive components do not guarantee sufficient protection. Without a digital security chip, the computer hardware is severely exposed to risks.
The security chip PS223 from Silicon Touch is popular, and you should avoid PSUs not using it or similar products, such as the PS332S.
Cables and Short Circuits
You can tell a lot about your PSU by looking at its internal wiring. A lack of heat shrink tubing, carelessly exposed solder joints, and components fastened with a glue gun are symptomatic of cheap and hazardous manufacturing. If unprotected cables are placed next to hot components, a PSU failure is nearly assured.
A final quality indicator is the circuit board material. Impregnated laminated paper (like the yellow boards in the pictures) is a sure sign of cost cutting. Fiber materials are much more durable and, perhaps more importantly, non-flammable.

UL Numbers From Underwriters Laboratories
"Underwriters Laboratories, an independent firm working with product safety certification, has been active in the field of product testing and preparation of safety standards for more than a century. UL evaluates more than 19,000 types of products, components, materials and systems annually. Every year more than 20 billion UL marks are placed on products from 66,000 different manufacturers. The UL Group and its network of service providers include 68 testing and certification labs worldwide, serving customers in 102 countries."--from the About UL page at

Essentially, this means that all PSUs sold on the North American market must be marked with an UL number. This number should identify the actual manufacturer of a product. However, not every PSU has such a number. UL number omission on a North American product might indicate poor quality.
Step 1: Reading the UL Number
To find the UL number, there's no need to open your PSU or desolder anything. Simply open your PC and look at the power supply's label. The UL number usually begins with an "E" followed by a string of numbers. See the three examples below.

Online UL Number Query:

Now let's find out more about your PSU. Go to the UL Online Certifications Directory and enter the UL number in the UL File Number field. If the number exists in the database, you should immediately see the result. If not, the number is invalid, fake, or the manufacturer no longer exists.

Companies: Casing Macron, Channel Well, Chenbro, Chieftec, CompUSA, Coba, Codegen, Cooler Master, Coolmax, Cooltek, Corsair, Deer, Dell, Delta, Dongguan Zhangmotou, Dynapower

Companies: Eagle Tech, Elwin Technology Ltd., Enermax, Enhance, Enlight, Etasis, Forepoint, Fortron, Foxconn, Foxlink, Fujitsu Siemens, Gigabyte, GPS, GTR, Hama, HEC, Hiper, Highscreen, High Performance Group, High Performance PC, High Power, Himere, Hipro, HP, Huntkey

Companies: Impervio, Inter-Tech, In Win, I-Star, ICP, Jersey, JOU JYE, JPAC, Just PC, Key Mouse, Kingwin, L & C, LC-Power, Leadman, Levicom, Li Shin, Lian-Li, Lite-On, Linkworld, Logisys, Mad Dog, Mapower, Masscool, Mean Well, MGE/XG, Mitac, MSI, Mushkin

Companies: Newton, Nexus, nMediaPC, NorthQ, NZXT, OCZ, Okia, PC Power & Cooling, Point of View, Powerman, Powertek, Powmax, Raidmax, RaptoxX, Rasurbo, Revoltec/Listan, Rosewill

Companies: San Hawk, Scythe, Seasonic, Seventeam, Sharkoon, Shuttle, SilenX, Silverstone, Sinan Power, Sino Tech, Sirtec, Solytech, Soyo, Sparkle, Spire, Startech, Sunbeam, Sun Pro, Sunfone, Super Flower /SFC, Tagan, Taiwan Youngyear, Thermaltake, Topower, TTGI, Tyan

Companies: Ultra, Unitek, Vantec, Win-Tact, Wintech, Wiseframe, XClio, Xigmatek, Xilence, Xion, X-Spice, Yesico, Zalman, Zippy

We want to stress two things in particular:
A PSU is not necessarily bad because it is cheap. But the lower the price, the more you'll likely have to skimp on safety and performance features. A high-quality PSU contains more expensive components. If you buy cheap, you might have to buy twice--or more.
A PSU is not automatically inferior because it was made by a contractor with which you aren't familiar. These companies make all kinds of products, from luxury brands to pure garbage. Again, it's a question of hitting different production targets. Is the product built for quality or aggressive cost reduction? The responsibility always lies with the buyer to recognize and reject products that are obviously unsuitable.
We will keep collecting data and update this list every once in a while, and we’d love to include your findings. Please use our feedback form to forward information that isn’t available in our listing!

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