Corsair HX850 PSU Review

Cross-Load Tests & Infrared Images

Our cross-load tests are described in detail here.

To generate the following charts, we set our loaders to auto mode through our custom-made software before trying more than 25,000 possible load combinations with the +12V, 5V and 3.3V rails. The load regulation deviations in each of the charts below were calculated by taking the nominal values of the rails (12V, 5V and 3.3V) as point zero. The ambient temperature was between at 30°C (86°F) to 32°C (89.6°F).

Load Regulation Charts

Efficiency Chart

For a small region, the PSU's efficiency falls within the 92-94% range. Otherwise, it's predominantly between 90-92%. Once we apply lots of stress to the minor rails, though, efficiency drops to 85-90%.

Ripple Charts

Infrared Images

We applied half-load for 10 minutes with the PSU's top cover and fan removed before taking photos with our modified FLIR E4 camera that delivers 320x240 IR resolution (76,800 pixels).

Temperatures inside the PSU are generally normal. However, we worry about the electrolytic caps, which are installed between the +12V boards. The operating temperatures of those caps are increased because both +12V boards naturally get hot, especially under high loads. Thankfully, airflow is unobstructed on the secondary side, so when the fan spins, the caps shouldn't become dangerously warm.

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6 comments
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  • ilogic450
    Thanks!
  • derekullo
    Would it be possible to do a comparison between the Corsair HX850 and the AX860?

    All digital sounds nice on paper, but how does it translate into power supply performance?

    Does the extra $12 for the AX860 give you a quantifiable difference between them?

    And if the AX860 does turn out to be superior in some way then why does the HX850 even exist in the first place?

    Corsair AX860 $181.99
    https://www.newegg.com/Product/Product.aspx?item=N82E16817139041

    Corsair HX850 $169.99
    https://www.newegg.com/Product/Product.aspx?Item=N82E16817139083


    I remember back in 2002 I blew my power supply while overclocking and playing Tron 2.0 .
    (The power supply didn't take out anything, just had to buy a new one.)

    Ever since then I've always used the highest priced AX line, with the rationale of never going cheap on my power supply again.
    (And being more conservative with my overclocks)
  • mauro2003_9
    The AX860 OEM is Seasonic.
  • Aris_Mp
    The AX860i has 1.42% higher overall performance score than the HX850 and the AX860 is very close to the AX860i. I would say that the performance of the AX860 and the HX850 is really close, however the second is much more silent.
  • Dark Lord of Tech
    Congrats to Corsair on another stellar PSU , and thanks for the review.
  • ElectrO_90
    The first paragraph talks about the HX850i and the new cables in this HX850.
    Where are the comparisons between the 2?
    Why even mention it, if you aren't going to show how much better the HX850 cables are, if at all?