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Corsair RM850x White PSU Review

Final Analysis

The white version of Corsair's RM850x offers the same high performance as its black counterpart, and is super quiet as well. We love the unique look of its paint job and individually sleeved cables. If you own a matching chassis or simply want a PSU that stands out from the crowd, the white RM850x and RM750x are both excellent options.

Compared to the black/charcoal RMx units at similar capacity points, the white ones cost $30 more due to those harder-to-manufacture cables. Given that a high-quality sleeving kit can cost anywhere from $80 to $100, though, a $30 premium isn't bad. Good looks don't come cheap, after all.

Corsair's RMx line is already popular among enthusiasts since all of its members offer high performance, good value ratings, and low noise output. These days, more and more users care about quiet operation, and PSUs play a big role in achieving this. A few years ago, aggressive fan profiles were preferred since efficiency levels were low. Inevitably, the PSU's fan had to cope with increased thermal loads. But now that the highest-end platforms offer sky-high efficiency, semi-passive modes are much more common and fans don't need intrusive rotational speeds to keep up with energy losses. Even the heat sinks in many PSUs are much smaller now. Corsair's RMx family doesn't employ a real heat sink for the +12V FETs.

Despite the rifle bearing fan, which can't match the lifetime of a true FDB-based fan, Corsair backs its RMx PSUs with an impressive 10-year warranty. This clearly shows confidence in the platform's reliability. Ten years sounds like a long time for rifle bearings. However, thanks to the semi-passive mode, we aren't expecting issues under normal conditions. Granted, that might not be the case if you use the RM850x in a mining rig.

The white RM850x stands alone, for the most part, until companies like EVGA and Seasonic decide to launch their own white models with similar capacity and comparably low noise output.


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  • stairmand
    I've got one of these and wish I had bought a different PSU and paid for cable mods instead. The in line caps are not too big a deal (lets not forget the whole point of the colour and cables IS the aesthetics) but the way the PCIe cables are wired (in a Y config) is terrible and makes it very hard to neatly cable.

    The combes are also relatively poor quality and don't clip together brilliantly especially as there are multiples wires used in a couple of pins.
    Reply
  • vapour
    Looks nice, but seems to behind Seasonic Focus Point and EVGA Supernova G2. Make better psus, Corsair!
    Reply
  • feelingtheblanks
    Hey Aris,

    Is there a possibility to retest one of those Evga Supernova G2 units, like G2 750, in terms of the new hold-up time tests?

    I read your Leadex Gold 550 review, where you find out the hold up time of that unit (and maybe the whole platform) is questionable and not really safe. So that made me think that the rest of the platform and also the Evga units are plagued by the same important mistake.

    I own a G2 750 and after reading that review and some forum threads, I'm a bit worried now.

    Hope you can help.

    Best
    Reply
  • turkey3_scratch
    20451514 said:
    Looks nice, but seems to behind Seasonic Focus Point and EVGA Supernova G2. Make better psus, Corsair!

    RMx have always been better than the G2 because they're quieter.
    Reply
  • Aris_Mp
    Unfortunately I don't have any G2 units any more, to test for hold-up time.
    Reply
  • feelingtheblanks
    20453647 said:
    Unfortunately I don't have any G2 units any more, to test for hold-up time.

    Thanks for the answer Aris,

    Do you think that these units are safe though? G3 850 seems fine on your tests. Are there dramatic differences between G2 750/850 and G3 850 in terms of bulk caps etc...? You have a rough estimation maybe?

    Best


    Reply
  • Aris_Mp
    I believe that the G2s are pretty good units and I would't hesitate to use them. Unfortunately I cannot estimate their hold-up time without testing them (something impossible now since they are EOL).
    Reply
  • turkey3_scratch
    20454054 said:
    20453647 said:
    Unfortunately I don't have any G2 units any more, to test for hold-up time.

    Thanks for the answer Aris,

    Do you think that these units are safe though? G3 850 seems fine on your tests. Are there dramatic differences between G2 750/850 and G3 850 in terms of bulk caps etc...? You have a rough estimation maybe?

    Best


    I looked into it before. The 650 G2 most likely has the problem where it drops the PWR_OK signal after the voltages go out of spec. The 550W should be fine. I'd assume the 750W is perfectly fine also. Not something to worry much about anyway.
    Reply
  • YoAndy
    My previous corsair GS700 fried my motherboard(lasted only 2 years of mild use)..
    Reply
  • turkey3_scratch
    20454749 said:
    My previous corsair GS700 fried my motherboard(lasted only 2 years of mild use)..

    Pretty sure those were some of the most unreliable units in history. RMA rates above 10% I believe.
    Reply