How THG Tests Power Supplies

No power, no dice: it's really that simple. All components in a PC system need electricity, and ever-increasing amounts of it, so the power supply has to come up with the goods. Manufacturers can claim what they like, but the claims don't always translate into reality, and very few users have a good idea about the power drawn by the individual components.

This is why we test power supplies ourselves. To help you understand the procedure we use, we will now shed some light on the issues involved, and explain our testing procedure.

Performance is always at the top of the list of a power supply's features, but the trick is to find out the device's actual power output, and whether voltages lie within the specified values. Voltage tolerances at all load levels are described in the ATX12V Power Supply Design Guide. This document is the technical basis for all power supplies, and the standards it contains are used for all our measurements.

We employ a special platform to test loads on power supplies. At its core are four electronic high-performance loads, each of which can handle a maximum current of 50 amperes. This setup enables us to record measurements extremely accurately. Conventional adjustable resistors are used for the standby voltage and the rarely used -12V and -5V paths. A network filter ensures that any interference pulses from the network do not distort our measurements.

Get a Free Website with Free Domain and Free Hosting

View the original article here

80 PLUS Gold: Four Efficient 700-850 W Power Supplies

Gamers and enthusiasts are always on the lookout for crème de la crème hardware. It's easy to pick winning CPUs and graphics cards; less so for PSUs. We put four 80 PLUS Gold devices from Antec, FSP, Seasonic, and SilverStone under the magnifying glass.

Computer stores are fond of advertising high-end PCs for power users. Although those systems can't hide behind weak processors or sub-standard graphics cards, unscrupulous builders do manage to save costs by using poorly-built or insufficiently-capable power supplies. Unfortunately, while they might work for a time, we've heard too many horror stories about performance-oriented configurations going up in smoke after a cheap PSU cried havoc and let slip the dogs of war.

In many expensive computers, cheap PSUs are a silent threat not only to general stability, but also long-term component health. The real high-end power supplies that you can appreciate years from now (but might not consider worth the extra premium today) often don't make the cut because of the fact that they cost more. All the devices included in this roundup are suitable for almost any enthusiast PC with a discrete graphics card or two.

We requested power supplies from a number of vendors able to provide a total output between 700 and 900 W, and achieve efficiency able to meet the 80 PLUS Gold standard. With Antec, FSP, Seasonic, and SilverStone in the mix, only brand name devices are represented.

The 80 PLUS standard emerged from the Generalized Internal Power Supply Efficiency Test Protocol, which was created by Ecos & EPRI almost 10 years ago. In 2004, 80 PLUS was specified as an initiative, and Seasonic was the first PSU maker to provide a compliant product by 2005. Only a year later, the Energy Star 4.0 specifications added 80 PLUS requirements. This spec went into effect in 2007 and it only took a few months for the industry to create hundreds of 80 PLUS-compliant products.

However, 80% efficiency clearly wasn’t enough. It quickly became obvious that higher efficiency is possible, and 80 PLUS revised the standard and added Bronze, Silver, and Gold certifications for even higher-efficiency power supplies. By October 2009, a Platinum standard was added for efficiency above 90%. Here is a quick overview on 80 PLUS efficiency level certifications:

80 PLUS Test Type115 V Internal Non-Redundant230 V Internal Redundant

While the step from 80 PLUS to 80 PLUS Platinum is significant and may translate into significant differences in power consumption, the steps between the three mainstream certifications (Bronze, Silver, and Gold) are less spectacular. Typically it makes very little sense to spend a lot of extra money upfront for an 80 PLUS device in an effort to save money on the power bill over time.

Effectively, reasonable devices with 80 PLUS Bronze or Silver certifications should do the trick. However, prices for Gold-certified 80 PLUS PSUs have come down quite a bit, and considering such a device is smart not only for its improved efficiency, but also because you can be even more confident in typically-great build quality. If you’re already on your way to spending big money on enthusiast hardware, it might make sense to spend a few more dollars on a superior power supply.

Without spilling the results right out of the gate, we can say that all of the 80 PLUS Gold PSUs we tested performed their tasks very well. And, aside from a few small lapses, they are highly suitable for use in real high-end PCs.

Get a Free Website with Free Domain and Free Hosting

View the original article here

Bang For Your Buck: Four 500 W Power Supplies Reviewed

Enthusiasts often say that you can never have too much performance. However, a 500W power supply is perfectly ample for a majority of mid-range PCs. This is one of those cases where a solid ratio of performance to price is preferable to gross excess.

Editor's Note: If you want more background on how power supply testing plays out here at Tom's Hardware, I recommend that you check out Soon At Tom's Hardware: Full-Scale Power Supply Testing before reading this piece.

Special attention gets paid to the power supply unit (PSU) these days, primarily in the high-performance and gaming community. No wonder, as the requirements of top-shelf PCs with multiple processors and modern 3D graphics cards are constantly increasing. Such computers will suck 800 W or more from the power supply under load, and for short periods that number can be substantially higher.

On the other hand, power supplies are often forgotten in offices and for everyday multimedia applications. Truth be told, compact and mid-range PCs don't require a high-performance power supply. However, investing in a high-quality power supply can pay off in several ways.

First, a good PSU guarantees a reliable and consistent supply of power to all components. This can help extend component longevity. Second, a highly energy efficient PSU helps reduce the energy consumption of a home or office. Additionally, other aspects, such as ergonomics, cable modularity, and cable length can simplify or complicate PC assembly. PSUs with good build quality also prevent nicked fingers or a less-than-optimal fit during installation. Trust us. We've seen it all.

We gathered a few mid-range models for this roundup. A top street price of $150 was our only prerequisite, and we settled on four 500 W models from Cooler Master, Enermax, FSP, and SilverStone. The coveted 80 PLUS logo is emblazoned on each box, except for SilverStone's.

Get a Free Website with Free Domain and Free Hosting

View the original article here

PC Power Supplies: More Important than You Think

Computers keep increasing their capabilities and their performance. These characteristics not only contribute to increases in their purchase costs, but also their costs of operation, particularly when it comes to power. Although AMD and Intel have curbed their high-flying ways - where CPUs with total power levels of up to 130 Watts were tamed using SpeedStep or Cool'n'Quiet - ATI/AMD and Nvidia's graphics cards continue to consume stratospheric amounts of wattage. As we reported in our German-language coverage Power-hungry Graphics Cards, power consumption levels at or over 200 Watts are not unusual. In dual-card configurations built around SLI or Crossfire technologies, graphics processing can add 500 watts or more to a system's total power consumption.

Such massive needs for power must be satisfied, and power supply manufacturers have reacted to meet them. At this year's Computex Taipei, numerous vendors introduced power supplies - also known as power supply units (PSUs) - rated as high as 2000 W. Gigabyte is one vendor that serves many global markets, and is perhaps best known for its motherboards and graphics cards. At that show, it introduced a new family of power supplies named Odin, after the one-eyed chief of the Norse pantheon, with capacities rated at 550, 680 and 800 Watts.

Power users and case modders alike have quested after the perfect PSU for some time now, driven as much by needs for high-end components as aesthetics and "bling". Thanks to the continuing debate on global climate change, this quest has begun to register for both OEM PC vendors and normal PC users as well. The following questions remain to be answered, however: "Are such monster power supplies really important?" and "Who really needs them, anyway?"

Join our discussion on this topic

Get a Free Website with Free Domain and Free Hosting

View the original article here

Three 1000 W 80 PLUS Gold-Certified Power Supplies Tested

We received a trio of 1000 W power supplies priced between $200 and $300, so we ran them through our usual suite of tests to see if they really live up to their 80 PLUS Gold certifications. Surprisingly, all three hiccuped during efficiency testing.

It's easy enough to assume that 80 PLUS Gold-certified PSUs with power ratings in excess of 1000 W are not built with the broad masses in mind. It takes a serious configuration to require such high power delivery ceilings. Nevertheless, the findings in this roundup make it pretty clear how much importance the manufacturers attach to the quality of their products. Even the slightest deficiency is exposed immediately at such high loads, and the negative effects on energy efficiency are often quite severe. We received three PSUs for this piece, and we put them all through our gauntlet.

Compared to our recent roundup of gaming PSUs where the manufacturers almost buried us in test samples, the range of products is much more manageable in the high-end space. We're looking at two 1000 W PSUs from OCZ and Rosewill, along with a 1250 W PSU from Sparkle. Can the Sparkle PSU exploit its significant power rating advantage in any way? And how will these 80 PLUS Gold perform at the low loads typical of an idle PC?

Also Tested: Standby Power Consumption, EuP Standard

The European Union’s Eco-design Directive 2009/125/EC, also known as the EuP (short for Energy-using Product), contains increased stringency regarding the standby mode power consumption of PSUs from the year 2010. As more and more manufacturers are advertising the EuP certification on their PSUs, we are introducing the appropriate test methods in our reviews. Unlike previous standby measurements made with the 5 V-sb rail active, there are no loads on the rails in the EuP tests. The PSU must manage a standby power consumption of less than 1 W.

Get a Free Website with Free Domain and Free Hosting

View the original article here

Who's Who In Power Supplies, 2011: Brands Vs. Manufacturers

Do you think that all power supplies are manufactured by the brand on the label? Think again. We show what makes a good PSU and reveal who builds them. You can actually find lots of quality (instead of just scrap metal) behind some of the budget labels.

With 472 entries associating power supply brands and manufacturers, our 2011 list is three times larger than it was last year. We owe a debt of thanks to all of the readers who sent us email and provided valuable feedback in the comments section of Who’s Who in Power Supplies: Brands, Labels, And OEMs. As of today, our list still doesn't cover all of the products on the market, an almost-impossible task due to the constantly fluctuating environment. But our database can at least help guide you away from costly bombs and toward true PSU bargains.

For those companies that don't manufacture their own products we list the most notable product series and, wherever possible, the associated base designs. This helps to classify unlabelled or rebadged power supplies based on a certain description or the use of a standard PCB.

Several new labels have started selling supplies from a handful of dubious manufacturers, and most of these products belong in the junk category. Low-cost PSUs are not suitable at all for serious systems. Widely-unknown labels are preceded by a questionable reputation, to say the least, and are often followed by smoke and an unpleasant aroma. Almost every time we try to give lesser-known units a chance, they invariably blow up in our faces. Soon, we'll publish another piece that helps identify some of the warning signs of a poorly-built power supply, hopefully preventing you from turning your next build into a ticking time bomb.

This article first appeared on November 12, 2010, and has since been added to and updated.

Who’s 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 then 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, Corsair, 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, change the label, 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.

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 checking out 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.

Get a Free Website with Free Domain and Free Hosting

View the original article here

Roundup: 12 Gaming Power Supplies Compared

Gamers demand a lot from their computers, starting with the PSU. Therefore, almost every PSU manufacturer sells products optimized for gaming PCs. We introduce ripple and noise testing in this roundup to further improve our power supply evaluations.

In previous power supply reviews, we focused on a specific power output range and tested performance and efficiency.

This time, we asked PSU manufacturers to send us products developed for a very specific and very demanding group: gamers. Are the so-called gaming PSUs really optimized for this segment? Or is that designation just an empty promise created by marketing departments? We looked at 12 different products to find answers.

New Test: Ripple & Noise

Following the requests of several manufacturers and our readers, we decided to include ripple and noise testing in our PSU reviews. According to the vendors asking about this test discipline, including these tests will highlight some obvious differences that should make it easy to draw conclusions regarding the electrical quality of a PSU, especially when it comes to high-performance units. As you'll see, this roundup will go on to show that not all manufacturers have done their homework in this area, and in some cases they don’t live up to our expectations--or the product specifications.

Ripple and noise testing is used to determine how accurately the circuits work to smooth out the DC voltage output. The goal is to produce a flat output, like you would get from a battery. Circuits of diodes and capacitors take care of this task as they convert alternating current (AC) to direct current (DC). Depending on the quality of these rectifier modules and components, the result shows more or less ripple and electrical noise. According to the ATX specifications, this value is not to exceed 120 mV for the 12 V rails. For all other ATX PSU voltages, the limit is 50 mV. A power supply that doesn't exceed these tolerances is good to go.

Huge Assortment, Huge Test

Up until now, we've generally compared five PSUs in our roundups. This is a natural limitation of test products, since we're paying for time in a professional testing facility. But it’s probably also because we're asking for products in very specific segments in order to make the comparisons as relevant as possible.

This time, we asked the manufacturers to send us gaming-oriented PSU products, without providing any specific criteria, and we received a veritable avalanche of submissions. Therefore, this review offers a broad spectrum of the market, represented by a total of 12 PSUs. Their power ratings fall between 580 and 850 W, and the efficiency certifications range from 80 PLUS to 80 PLUS Gold. Prices differ quite a bit, with the cheapest starting at around $90, while the most expensive offerings sit around twice that number. In addition to the manufacturers represented in our previous tests, Antec, Chieftec, Cooler Master, Corsair, Cougar, Enermax, and Seasonic, this time we have four newcomers to our test labs: be quiet!, NZXT, OCZ, and Sparkle.

Get a Free Website with Free Domain and Free Hosting

View the original article here