Testing Overview

We changed our testing procedures slightly in our last article. We have added a low input voltage test which is in this case again 100VAC. This power supply is rated from 100 to 240VAC thus we couldn't perform a 90VAC test. We are testing the power supplies with programmable loads from Chroma. If you would like to know more about our testing methodology, equipment, and environment, please read our Power Supply Test Methodology overview.

Note: The rails of the power supply can be regulated through the included software. All of our results are made with standard settings without any regulation.

Before we start with the results we would like to clarify the tables from each rail. Some readers were asking after the last review why we wrote 100% load and we had less than the stated 750W. This is easy to explain. In our static tests we are testing a load from 100% and not an output of 100%. We calculate the load for each rail according to the respective combined power and stated power for each line, because the stated power for each line is not the actual power it can deliver together with the other rails in use.

In our review today we have four 12V rails with two of them rated at 18A the other two at 25A. The combined power for these four rails is 62A which is around 15A per rail. The results shown in the tables (in the second column) indicate how much amperage we are using on the rail. The third column shows the resulting wattage, which is the product of the amperage and voltage of that particular line (P = IV). As the voltages drop during testing, the final result is always lower than the actual stated rating of the power supply.

For example: 19.95A is the load for the 3.30V rail at 100%. If the power supply could deliver 19.95A at 3.30V we would have a result of 63.525W and not 60.06W like we will see on the next page. By the time we add this added with the 5V and four 12V rails we get 100% theoretical load at only 770W instead of 800W. This does not mean that the PSU cannot deliver 800W however, and thus we have added more tests towards the end of the article to determine each rail's maximum capacity.

Inside, Cont'd 3.3V DC Output
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  • strikeback03 - Tuesday, July 24, 2007 - link

    Does the software need to be running for the voltage regulation to work? Or can you make changes then close the software and have the changes still work on the PSU?

    Also I'd guess if UV lighting is that useful for a case you could swap the blue LEDs for some UV ones - looks like enough wire is exposed to cut the blue ones and solder in UV ones.
  • Oberst - Tuesday, July 24, 2007 - link

    Hello,
    nice review (i wouldn't expect anything else of you). But I've got a question about the measuring-software: Was it reliable, when measuring voltages? You already mentioned, that the wattage was not reliable. So I'd like to know, if that was because of wrong measured amps or volts.
    greets Oberst.
  • Christoph Katzer - Tuesday, July 24, 2007 - link

    Voltages have been quite accurate; amps have been wrong in almost every case.
  • qpwoei - Tuesday, July 24, 2007 - link

    Once you've got the ripple measurements sorted out, it'd be nice to get some scope traces as the load changes. Poor transient response of the rails can cause all sorts of hard-to-diagnose problems in the real world.
  • Christoph Katzer - Tuesday, July 24, 2007 - link

    We use a scope to follow response on the rails but until now we feel the data is not good enough to present. If there would be something to extraordinary to tell we surely would.
  • bob4432 - Tuesday, July 24, 2007 - link

    what about that? a good quality unit, the Corsair 520HX seems to be a lot of people's favorite lately, how does it really stack up? or some of the FSP "Green" units - are they really that efficient? what about seasonic - really as good as everyone says?

    these reports are all fine and dandy, but you are catering to possibly 5% of your user base, yes even here 800W is extreme overkill.

    and it is not a $$$ issue but rather a reality issue. i am surprised you guys testing these are continuing the thought process by only reviewing the upper wattage units and thus making everyone think they need one when they don't - people on review 750W psus, so i must need one...come on guys
  • Christoph Katzer - Tuesday, July 24, 2007 - link

    Will come. No worries about that. At the moment we are just starting as you can see and of course every company wants to have the best PSU tested first. We'll have lower ones very soon but need to work on that mountain of PSUs here first. With 380w you will see a Seasonic pretty soon for example.
  • bob4432 - Tuesday, July 24, 2007 - link

    will definitely be looking forward to them :)
  • ATWindsor - Tuesday, July 24, 2007 - link

    I disagree that an OCP per rail i s a good thing, it onyl makes using the PSU more of a hassle, since you can draw a lot less from the PSU on 12V than the specs would make possible, if you are unlucky and draw most of it from one rail. Several manufacturers have one big rail without any know safety-problems, having an OCP for the combined drav from the 12V-lines however is a good thing.

    AtW
  • dare2savefreedom - Tuesday, July 24, 2007 - link

    I would be interested in knowing how a psu runs with dual 8800gtxs in virginia in summertime in an old house with a window air conditioner.

    Not these theoretical white glove clean room lab environment tests.

    triple sli 8800gtx?

    come one stop playing with your iphone.

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