Temperatures, Fan Speed, and Acoustics


We really don't like CWT's heatsink design on their current power supplies, and the temperature readings show that our feelings are not without merit. The third heatsink reaches almost 80°C, which is quite hot for a modern power supply -- and this is running in a comfortable 25°C environment; imagine how hot the power supply would get with higher ambient temperatures. The result of higher temperatures is that the fan will need to run at maximum speed all the time. The exhaust temperature does stay relatively close to that of the first two heatsinks, which is good; that means they are doing a good job of transferring heat into the airflow and getting the heat out of the power supply. The problem is that the third heatsink has a temperature 20°C higher than the others.


The fan spins at ~1100 RPM at lower loads of up to 20%. The fan begins spinning much faster at 50% load, even though temperatures are still reasonable. The first two heatsinks are only 10°C higher, so the dramatic ramp in fan speed shouldn't be necessary yet, but the fan is already spinning at around 1600 RPM. Maximum fan speed is reached at ~80% load, and it appears fan speed is being regulated by the temperature of the third heatsink as we can see above that the temperature is quite a bit higher.


The TX750W fan is not silent, and a moderate increase in fan speed results in a dramatic increase in noise levels. At minimal load, the power supply generates 21dB(A) of noise, which isn't terrible but it isn't great either -- you wouldn't normally notice the power supply when it's installed in a system at low loads. At 50% load the volume increases 7dB(A), which definitely becomes audible. You definitely do not want to run at anything near maximum load, however, as 80% load results in 39dB(A) and 100% load is 40dB(A)! If you are interested in silence (or even near silence), there are without doubt better power supplies.

Efficiency and PFC Conclusion
Comments Locked

26 Comments

View All Comments

  • 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.

Log in

Don't have an account? Sign up now