Testing with the Chroma ATE Programmable Load


Our test equipment consists of two Chroma programmable DC Loads that enable us to test power supplies with an output of up to 1500W. The biggest advantage of the Chroma DC Loads is simply the high precision it provides. It can measure differences as small as 0.001V and 0.0001A, which will provide us with best-in-class results.

When programming the Chroma with specific amounts of load calculated according to the ATX norm, we are able to load power supplies to an exact percentage. We can now show results at every specific percentage needed. To get the best overview of a power supply, we load each unit with 10%, 20%, 50%, 80%, 100%, and 110% of the specified output. This is easy to calculate for a 1000W power supply: the 10% load is 100W and 110% load is 1100W. Remember that this is the amount of power the PSU delivers; due to inefficiencies, a power supply will actually draw more power from the wall.

Note: If you would like to know more about our testing methodology, equipment, and environment, please read our PSU testing overview.

We have added an additional 10% on the highest load to see how the units perform with overload. This test will be performed in all future reviews. The overload test is performed at room temperature as well as under more stressful conditions; to ensure we are not too cruel to the power supplies, we will keep the ambient temperature at 50°C in the stress test. Experience shows that many units can stand the overload at room temperature but will experience problems with higher temperature and overload together. Only the best-built units will survive this.


The Testing Environment

There is one flaw in testing power supplies with programmable loads while trying to measure the sound pressure levels at the same time. Because the programmable loads get very loud, there is no chance of hearing the power supply on the test stand. In order to make accurate measurements of the noise levels we needed a way to separate the test unit and the programmable loads. Our solution was to build a very thick box around the unit.


We concluded that a five-layer box with a total thickness of 6" (15cm) containing two layers of wood and three layers of special foam would suffice. It is designed as a box within a box. The inner box does not touch any part of the outer box, making it difficult for acoustic noise to pass through in the form of vibration. Each box is isolated on both sides with a layer of heavy foam that is normally used to insulate engines. On the inside we have an additional layer of 4" (10cm) thick pyramidal foam on every side of the box to eliminate the acoustic waves coming from the test object as well as we can.


To ensure a completely closed system we installed the printed circuit board that the connectors of the power supply are attached to inside the anechoic room/box. In other box designs, you would need to put all the cables through the wall. Unfortunately, that would result in the inside of the box not being fully isolated anymore. Our design keeps everything that needs to be connected inside of the box and maintains isolation.

Internals DC Output Stability and Quality
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  • dh003i - Saturday, December 6, 2008 - link

    This is really horrible on Enermax's part. It was said that the PSU would be available at the end of the month (then Novemeber), at the latest; here it is the end of the first week of December, and the thing still isn't to be seen anywhere. Maybe Enermax will decide to bless us by making it available before Christmas.

    When you announce the availability of a product, it damn well better be available.
  • dh003i - Monday, December 8, 2008 - link

    I e-mailed Enermax and got a respond from them saying "The revolution should be available in about two weeks." That's December 22nd, or just around Christmas. So we'll see if that ends up being the case.
  • s1ugh34d - Wednesday, November 12, 2008 - link

    Enermax PSU. My liberty 400w over spins the fan, So I pulled the fans cable out, and hooked it up to 5v, It's always quiet right around 800RPMs...

    My Q6600 dual 8800GT's runs on a 610w PCP&C silencer. There is only a few small situations were over 750w is necessary.
  • dh003i - Wednesday, November 12, 2008 - link

    So-far, this sounds great, but almost like vaporware (except Anandtech has an actual working sample). I mean, when will this thing be available? I'm building a new workstation for myself, and have held out purchasing the CoolerMaster 1200W UCP because of this new Enermax Revolution 1050W, which is modular. But I don't know how long I can wait. It'd be nice if Enermax gave us some kind of clue as to when the thing will be available.
  • Christoph Katzer - Wednesday, November 12, 2008 - link

    Enermax says that the first shipments will arrive at the branch offices in the end of this month latest.
  • gochichi - Monday, November 10, 2008 - link

    Good point, cause Hybrid SUVs are still SUVs and this guy is a 1050W powersupply... definitely an "SUV".

    This thing is really GOOD looking actually. To those of you who ask, why even write an article of a 1050W power supply? I say, this is an enthusiast's site... of course it should be covered.

    I unfortunately won't be buying this beauty, but if I were more enthusiast-like (kind of past the stage now sadly)I would certainly consider it. $330.00 is a lot of money, but it's not so bad. You figure in the things prone to become obsolete are video cards (two-cards at least for a system with this power supply yes?) Those will run $200+ each. CPU... say $300+, motherboard say $150-$200.00 and on and on. If you're going to do that sort of build you may as well slap this thing on there.

    I'm happy with my switch to the sub-$500 computer space for desktops. But it's boring, and this power supply isn't. I also own a Corolla, it doesn't mean a Lamborgini Murcielago is "irrelevant".

    Oh just in case you've been in a cave for a few years. $150.00 buys you an awesome video card. Even if you're old like me, you should really get one just for goodness' sake.

  • CEO Ballmer - Saturday, November 8, 2008 - link

    I like the specs on this!

    http://fakesteveballmer.blogspot.com">http://fakesteveballmer.blogspot.com
  • iwodo - Friday, November 7, 2008 - link

    Thanks for all the hateful comment. But as far as i read, even a CoreQX97xx with Geforce GTX 280, as stated in the Corei7 review, only uses 300W at peak. ( And Corei7 uses less then that )

    Double that, so you have a Dual Quad Core, Geforce 280GTX 280 SLI, you will still ONLY arrive to 600W at peak.

    So may be the article "Debunking the PSU Myth" never got enough people read it.

    And this may be the second dumpest question ever as someone would post.
  • MrBlastman - Friday, November 7, 2008 - link

    Yes, exploded - as in a shower of sparks, loud bang and the force was so strong it broke the plastic mounting bracket where the heat sink attaches to my CPU...

    Along with thousands of other people's Enermax PSU's exploding, I am very afraid to purchase another Enermax PSU. I used to be a stalwart supporter of them - they made great stuff. But... after hearing of others warranty'ing their PSU only to get another one, or a third one that exploded, I decided to move on to something else.

    I hope they have finally fixed these problems.
  • xaris106 - Friday, November 7, 2008 - link

    how come don't you do step load tests?
    It would be really interesting and informative to see transient responses, settling times and overshoots. Please consider it.

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