Efficiency and PFC


As mentioned already, we did not expect to see extremely high efficiency, since previous CWT manufactured power supplies generally top out at 85%. 230VAC reaches that same efficiency, but efficiency with lower input voltages is far worse, particularly in terms of the curve -- the 120VAC and 90VAC inputs both show a precipitous drop after around 400W. Differences between the three curves is rather startling, hitting two different recommendations for ideal loads. With 230VAC, you can easily run this power supply with anything from a 130W to a 700W load, which is a very large range. For 120VAC, the range shrinks to 130W to 500W for best efficiency. If you happen to use 90VAC, you would probably be best served by a different power supply, but you can at least get above 80% with a load of 200W to 500W.


Power factor correction is always much higher with lower input voltages, but people in Europe will have to make do with only .97 at medium load. The PFC results for the TX750W are definitely worse than many of the other power supplies we've tested, particularly with 230VAC.

DC Output Stability and Quality Temperatures, Fan Speed, and Acoustics
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  • Martimus - Thursday, November 6, 2008 - link

    Holy Voltage Ripple Batman!

    I can't believe that a Corsair PSU is that bad at load. If I were running the test, I would double check to make sure I wasn't loading it improperly, because I wouldn't expect such a poor showing. I kind of hope that it was an error on your part, since I don't know any other manufacturers that make silent PSU's with the quality Corsair usually provides. PCP&C are always rock solid, but they usually are a little loud.
  • OddJensen - Thursday, November 6, 2008 - link

    Well, I'm very happy with my Corsair units, and so are the people which I recommended them to. It's good quality without being extremely pricey. I trust mine as much as any other high quality brand. Haven't gotten a TX750 yet tho, I've mostly gone with the Seasonic sourced ones.
  • billt - Tuesday, November 4, 2008 - link

    I have two Corsairs's where OEM is Seasonic; they are great and the reviews reflect that. The non-Seasonic Corsairs are not the same quality, as this review reflects
  • XiZeL - Friday, October 31, 2008 - link

    i dont get why it wont do crossfire...
  • JarredWalton - Sunday, November 2, 2008 - link

    It will do CrossFire just fine - it's just not CF certified by AMD/ATI. But then, is that even something that they do? I don't know.
  • Barbarossa - Tuesday, November 4, 2008 - link

    Actually the TX750 is certified as well:
    http://game.amd.com/us-en/crossfirex_components.as...">http://game.amd.com/us-en/crossfirex_components.as...


  • poohbear - Thursday, October 30, 2008 - link


    "We also received an HX520W recently"

    recently? This psu was one of corsairs first and its like 2 years old now, how come u're just receiving it now??
  • Christoph Katzer - Friday, October 31, 2008 - link

    I don't know why it's not clear that there are a few PSUs more than just Corsairs. We do our best but can't have all the time the latest stuff from each company. And like in this case if we forget a unit we test it later again after it settled.
  • Amart - Thursday, October 30, 2008 - link

    Excellent review, especially considering the price changes on the market. I recently upgraded my PSU and this one was one of the considerations. I went with the PCP&C 610 Silencer, slightly less expensive and I like the Continuous @ 40c guarantee that they offer.

    By the way, the most recent BFG models in the price range also offer the same "40c" performance guarantee and get excellent reviews.

    I don't know why Corsair stopped using that as part of promoting their products.
  • Barbarossa - Thursday, October 30, 2008 - link

    Actually, all the TX750 is Continuous @ 50C.

    The only PSU we sell that's rated @ 40C is the CX400.

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