AnandTech Power Supply Test Methodology
by Christoph Katzer on July 12, 2007 12:00 AM EST- Posted in
- Cases/Cooling/PSUs
Conclusion... for now
For many, power supplies are unfortunately still not considered an important component, but this attitude is definitively a mistake. Power supplies deliver the voltage to each and every single component in the PC and make them work. It is the heart of the system and the provided electricity works like blood in the human body. If the delivered electricity is faulty or unstable it can ruin even the greatest high-end rig instantly.
It is important that readers understand the importance of power supplies in today's PCs and we will do our part from now on to deliver the necessary tests. In addition we will explore the manufacturers themselves; good quality starts with a good engineering team that develops upcoming power supplies. We will visit the offices and factories of the manufacturers to show how and where power supplies are made.
When testing power supplies we will pay attention to important aspects of the units. It begins with the design of the PCB and the components used. A power supply might look very good from the outside but the build quality and structure inside could be just rubbish. To help determine the quality of these aspects of a power supply, we will open the test units and analyze the structure and important components on it. These days, power supply efficiency is a very important factor to consider, and it is very dependent on the components that are used. As we will see in the various reviews, better components result in improved efficiency as well as improved results in our other tests.
PCs often play an integral role in today's households. To make having them around more pleasant, it is very important to eliminate - or at least reduce - any noise pollution from the PC. By looking at the temperature of the heatsinks and the exhausted air and by checking the fan speed, we can get a better idea of what design decisions have been made in regards to reducing noise, as well as whether or not the design decisions are effective. Nothing is worse than a noisy power supply that still gets hot!
As a final thought, our tests are based on today's applications and circumstances, but we will also be pushing power supplies to their limits. If a power supply fails during testing, that doesn't necessarily mean it's a truly bad design. Failures can occur for a variety of reasons, and we will be sure to provide a detailed explanation of any failures, why they happen, and what they mean in the broader view of things. For example, we may see a few PSUs that perform extremely well, provided you don't exceed certain loads on some of the voltage rails.
Now that we have introduced our test equipment all that remains is to commence the actual testing and publication of results. Of course, that's not the end of the story, and we will be able to build opinions that will shape our future testing. We took a great deal of time planning, developing, and building our power supply test lab and we are sure it will do what it was built for: to deliver the most accurate and meaningful results possible. Stay tuned as we begin to cover this important area of computer components.
For many, power supplies are unfortunately still not considered an important component, but this attitude is definitively a mistake. Power supplies deliver the voltage to each and every single component in the PC and make them work. It is the heart of the system and the provided electricity works like blood in the human body. If the delivered electricity is faulty or unstable it can ruin even the greatest high-end rig instantly.
It is important that readers understand the importance of power supplies in today's PCs and we will do our part from now on to deliver the necessary tests. In addition we will explore the manufacturers themselves; good quality starts with a good engineering team that develops upcoming power supplies. We will visit the offices and factories of the manufacturers to show how and where power supplies are made.
When testing power supplies we will pay attention to important aspects of the units. It begins with the design of the PCB and the components used. A power supply might look very good from the outside but the build quality and structure inside could be just rubbish. To help determine the quality of these aspects of a power supply, we will open the test units and analyze the structure and important components on it. These days, power supply efficiency is a very important factor to consider, and it is very dependent on the components that are used. As we will see in the various reviews, better components result in improved efficiency as well as improved results in our other tests.
PCs often play an integral role in today's households. To make having them around more pleasant, it is very important to eliminate - or at least reduce - any noise pollution from the PC. By looking at the temperature of the heatsinks and the exhausted air and by checking the fan speed, we can get a better idea of what design decisions have been made in regards to reducing noise, as well as whether or not the design decisions are effective. Nothing is worse than a noisy power supply that still gets hot!
As a final thought, our tests are based on today's applications and circumstances, but we will also be pushing power supplies to their limits. If a power supply fails during testing, that doesn't necessarily mean it's a truly bad design. Failures can occur for a variety of reasons, and we will be sure to provide a detailed explanation of any failures, why they happen, and what they mean in the broader view of things. For example, we may see a few PSUs that perform extremely well, provided you don't exceed certain loads on some of the voltage rails.
Now that we have introduced our test equipment all that remains is to commence the actual testing and publication of results. Of course, that's not the end of the story, and we will be able to build opinions that will shape our future testing. We took a great deal of time planning, developing, and building our power supply test lab and we are sure it will do what it was built for: to deliver the most accurate and meaningful results possible. Stay tuned as we begin to cover this important area of computer components.
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crimson117 - Thursday, July 12, 2007 - link
Good point. Just because a certain digital camera fails when it is submerged underwater, it doesn't mean all users should stick to only buying waterproof cameras. You'd still have a great camera, provided you keep it out of the water.
crimson117 - Thursday, July 12, 2007 - link
<quote>The ambient temperature around the power supply will constantly grow with the time of the test. It will be placed in the same set of conditions it will experience in a real system, where the temperature rises over time.</quote>I'm very glad to see this highlighted in your review strategy.
It always irks me when I see temperature scores of heatsinks which don't consider the variable temperature of the cooling substance (the air) that was used!
If you blow hot 90 degree air over something, the best it can do is cool that something to 90 degrees. If you blast a heatsink with cool compressed air, you'd get much lower heatsink temperatures.
Rocket321 - Thursday, July 12, 2007 - link
About that 5 layer box...I re-read that page a couple times but don't get it. How do you connect the PS unit to the programmable load without running a cable through the wall of the box? If I'm reading it right, you are using the internal PCB to reduce the # of cables you run through the wall to a single cable...?
I'm just curious as it wasn't immediatly clear what was going on there.
Otherwise I applaud you for the new branch of quality reviews you're starting. I look forward to the first review!
nrb - Thursday, July 12, 2007 - link
I'm slightly concerned by this statement: I would urge you not to start doing PSU reviews until you have got the measurement of ripple figured out. It's one of the most important measures of PSU performance, IMNSHO.kaborka - Saturday, July 14, 2007 - link
I second that. Measuring ripple on my scope under various loads is the first thing I do when I get a new PSU. I have an old surplus Tektronix I use. I would not be interested in any reviews that don't include ripple measurements -- it would be useless.But Thank You, THANK YOU for finally doing serious PSU tests. The sites that do fluff pieces about the latest shiny boxes have always irritated me no end!
EODetroit - Thursday, July 12, 2007 - link
HardOCP pretty much is the gold standard on real, tough, power supply reviews atm. It will be interesting to see if you get the same results as they do.One thing that happens all the time in the HardOCP reviews is that a PSU will work great up to about 75% of its rating, then fail or get out of spec. My question is... will you consider that a failure or will you just recommend the PSU as long as you don't go over 75% ? No one runs a PSU fully loaded on purpose anyways.
One more thing slightly off topic... how come Anand (and everyone else in the biz) is willing to load a PSU to the max but won't review a motherboard loaded with the maximum "supported" memory? The latter is a much bigger problem imo, and with 64 bit OSes now commonplace that can make use of all the memory in a computer, the time is right to start reviewing MBs that supposedly support 8 GB of ram... while actually loaded with 8 GB of ram.
CrystalBay - Thursday, July 12, 2007 - link
So how is PCP&C's 750 Silencer gonna stack up with it's 80mm fan???End The Power Supply Myths AT........
strikeback03 - Thursday, July 12, 2007 - link
I recently bought some motherboards to build desktop systems for some of our grad students. They claim support for 16GB RAM, but since they only have 2 slots for RAM testing 16GB falls somewhere between "extremely expensive" and "impossible".Martimus - Thursday, July 12, 2007 - link
I would like to see that as well. MB's performance with a full load of RAM. (Actually I would want to know if there are any other issues when you run it like that.)strikeback03 - Thursday, July 12, 2007 - link
Nice new toys:)On the Temperature page where it says "We will start at a room temperature of 77°F (25°C)" perhaps mention should be made that the "room" is actually a sealed box, which appears to have far less air volume (and circulation) than the average room, so the air will get far warmer than it ever should in an actual case.