Cooler Master UCP 900W
by Christoph Katzer on July 29, 2008 3:00 AM EST- Posted in
- Cases/Cooling/PSUs
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.
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33 Comments
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JarredWalton - Tuesday, July 29, 2008 - link
"We see very little voltage drop on the rails, which is very good. All of the rails are within 2% to 2.5% of regulation, starting slightly higher than the target voltage and dropping slightly below target at higher loads. Ripple on the 12V rails is also exceptionally good, measuring at most 8mV. Lower voltage rails also perform decently, though not quite as good, measuring up to 21mV. The ability of this power supply to deliver the required wattage with little voltage drop even at higher loads leaves us with a good impression."Posting a graph that shows ripple isn't really any more informative than what we did right there: up to 8mV ripple on the 12V rails and 21mV on the 3.3V and 5V lines. You might want to read the text a bit more closely before firing off complaints. We state in the conclusion that the PSU has very good ripple results, and I guess that's probably as far as you got? The previous several pages of test results are there for a reason.
Amart - Wednesday, July 30, 2008 - link
A graph educates people, and shows that you've performed the necessary readings to construct it. Ripple/Noise is arguably one of the most important graphs to have on a review.Sure, you had 'something' in this review, which is an improvement over the last few months.
Christoph Katzer - Tuesday, July 29, 2008 - link
With 78mV no company in the high-end field would have released the product...mindless1 - Tuesday, July 29, 2008 - link
Do you have any evidence that 78mV of ripple has caused any problems by itself, isolated as the variable? The powered parts themselves cause more than 78mV of ripple local to them, where it might matter if it ever did - this if you had a hypothetically perfect 0mV ripple PSU.Zak - Tuesday, July 29, 2008 - link
I found CM products to have competitive prices - but I don't shop for high end stuff - and I've always received their rebates.nycromes - Tuesday, July 29, 2008 - link
I too have only had good experiences with their products and rebates. I have heard that others have experienced problems with rebates, but I don't usually hear many complaints regarding their products.I guess that some people must get a different experience than others, the question is which one of us had the normal experience and which one of us got lucky. Until I have a bad experience, I am sticking with my Coolermaster products.
Glenn - Tuesday, July 29, 2008 - link
You forgot to mention the business model coolermaster has relied on. Sell your product that has a worth of about $25 for retail price of $75 and then offer a $65 rebate that will likely not get paid!Then, when the customer has problems with the product, just make the process to repair or replace so difficult, that only the most persistant buyers will percivere the process to get something done!
Hey, it must be working for them!
JEDIYoda - Tuesday, July 29, 2008 - link
so what does anything you say have to do with this review?For that matter can you back up what your claiming with links??
Glenn - Tuesday, July 29, 2008 - link
It has everything to do with any Coolermaster product review! If the company is poor on customer support, then it affects the value equation for prudent buyers. Sorry you don't understand!Do some reading-
JEDIYoda - Wednesday, July 30, 2008 - link
I do understand very well! It is you that has a axe to grind against the Coolermaster products.The company support and how they handle problems has nothing at all to do with this review of the product!!
Yoyr bitch is against the compant itself...the 2 are very seperate!!
As usual a very well done review!!