Corsair RM850x White PSU Review

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By Aris Mpitziopoulos
published

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Ripple Measurements

To learn how we measure ripple, please click here.

The following table includes the ripple levels we measured on the RM850x's rails. The limits, according to the ATX specification, are 120mV (+12V) and 50mV (5V, 3.3V and 5VSB).

Swipe to scroll horizontally
Test12V5V3.3V5VSBPass/Fail
10% Load3.3mV3.8mV4.4mV3.3mVPass
20% Load3.9mV5.3mV5.6mV5.0mVPass
30% Load5.0mV5.2mV5.5mV4.9mVPass
40% Load5.7mV5.3mV6.2mV6.1mVPass
50% Load6.5mV5.7mV7.0mV7.2mVPass
60% Load7.0mV7.4mV8.1mV9.0mVPass
70% Load7.9mV7.9mV9.8mV9.9mVPass
80% Load8.7mV8.6mV10.9mV12.3mVPass
90% Load10.3mV8.9mV10.9mV12.8mVPass
100% Load11.9mV12.2mV11.9mV16.8mVPass
110% Load14.8mV10.5mV12.5mV15.6mVPass
Cross-Load 15.5mV11.6mV11.2mV8.0mVPass
Cross-Load 211.8mV7.5mV9.1mV14.2mVPass
Image 1 of 4

Ripple suppression is excellent thanks to a good platform and extra in-cable caps.

Ripple Oscilloscope Screenshots

The following oscilloscope screenshots illustrate the AC ripple and noise registered on the main rails (+12V, 5V, 3.3V and 5VSB). The bigger the fluctuations on the screen, the bigger the ripple/noise. We set 0.01 V/Div (each vertical division/box equals 0.01V) as the standard for all measurements.

Ripple At Full Load

Image 1 of 4

Ripple At 110-Percent Load

Image 1 of 4

Ripple At Cross-Load 1

Image 1 of 4

Ripple At Cross-Load 2

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Aris Mpitziopoulos
Contributing Editor

Aris Mpitziopoulos is a Contributing Editor at Tom's Hardware US, covering PSUs.

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10 Comments Comment from the forums
  • 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