Internals


Opening up this unit we find a typical Acbel layout and heatsink design. We saw another power supply from a German company rated at 500W that used the same layout and reached an impressive 88% efficiency. With this power supply boasting the 80Plus Silver certification, we expect it to reach a similar level, so it seems Acbel has really made some progress during the last couple of years. Prior to that, we rarely saw anything but boring, mediocre designs from Acbel, which is why many of Cooler Master's previous products offered only average performance compared to the competition. Now Acbel seems to be pushing newer technologies, and we find several solid polymer aluminum (SPA) capacitors on the secondary side.

Looking at the overall build, and starting from the power input, we find a heavy-duty filtering stage, though several parts are not really secured to anything. The large sister PCB on the right side holds the standby circuit and uses reasonable quality parts. The main capacitors come from Hitachi, which is relatively common in high-end PSUs these days, although this time there are three capacitors. They are all rated at 390µF and 400V, and the three caps are a very nice addition.

On the secondary side, as mentioned above, we see many solid capacitors and a few from Ltec Taiwan. Looking closer at the PCB, there are some indications that there are six 12V rails, but two of the rails won't be in use since this is only a 900W power supply. There's little doubt that we will see a similar design rated at up to 1200W with six rails in the future.

Cables and Connectors Testing with the Chroma ATE Programmable Load
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  • andlcs - Wednesday, July 30, 2008 - link

    Solid polymer capacitors are ELITE brand.
    http://www.chinsan.com/product/index.asp?id=22">http://www.chinsan.com/product/index.asp?id=22
  • sheh - Tuesday, July 29, 2008 - link

    20% load efficiency at is lower than 85% regardless of input voltage.
  • strikeback03 - Tuesday, July 29, 2008 - link

    IIRC they test by the ATX methodology, not the 80Plus loading, which might account for the difference.
  • MrOblivious - Tuesday, July 29, 2008 - link

    Or it could be the unit to unit variation, the different temperature, or the different load pattern, etc. ;)
  • JarredWalton - Tuesday, July 29, 2008 - link

    Definitely true. The 80Plus loading methodology differs from the standard ATX loading, and that can easily account for the 1-2% difference between what Christoph measured and what CM reports.
  • MrOblivious - Tuesday, July 29, 2008 - link

    80Plus does list what the requirements for certification on each test report (115v 60hz) and the load steps used to accomplish them. You can see the UCP report here: http://www.80plus.org/manu/psu/psu_reports/SP215_C...">http://www.80plus.org/manu/psu/psu_repo..._MASTER_...

    They don't list the temperature there but IIRC it is 25c (will have to check when I get home). Also, 80 Plus Silver is 85-88-85% not 82-85-82% as it seems to be indicated.
  • tomoyo - Tuesday, July 29, 2008 - link

    I was just about to mention this as there's some misinformation on 80plus scattered about in the article. Hopefully you'll clean that up soon. To me it's a pretty big achievement to get 85-88-85 at 25C on 115V on a huge 900w psu like this one. One thing I've noticed is that some of the new low power psu models are showing extremely high low wattage efficiency such as 90-92%. Some of these include the two dell 80plus silver models and some of the new actel ones. 80plus Bronze is much easier to achieve as most 80plus psu's are already near 85% in the middle range.
  • JarredWalton - Tuesday, July 29, 2008 - link

    "80Plus Bronze requires at least 82% efficiency at 20% load, 85% efficiency at 50% load, and 82% efficiency at 100% load. 80Plus Silver bumps the requirements up to 85%/88%/85% for the same 20%/50%/100% loads. In short, the Cooler Master 900W UCP had better be able to reach 88% efficiency."

    I'm not sure how that's at all confusing. As to the UCP 900W actually achieving Silver in our tests, it does appear to fall just short at the 20% load mark, but only by ~1% (84% efficiency when it's supposed to be 85%). I'm not going to worry overly much on that point, as there's a certain margin of error in testing.
  • MrOblivious - Tuesday, July 29, 2008 - link

    "Before you get too carried away with the high efficiency, however, we need to rain on your parade a bit. The 80Plus Silver badge means that most users will get at least 82% efficiency, but even 20% load represents a power output of 180W, which for an idle system represents a significant amount of high-end hardware."

    Since that is NOT what 80Plus Silver means it could be a bit misleading.
  • JarredWalton - Tuesday, July 29, 2008 - link

    Ah... I see my typo. I put that paragraph in, and apparently hit a 2 instead of 5. Should be 85% there, you're right....

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