Corsair RM850x V2 PSU Review: Smaller And Quieter!

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Load Regulation, Hold-Up Time & Inrush Current

To learn more about our PSU tests and methodology, please check out How We Test Power Supply Units. 

Primary Rails And 5VSB Load Regulation

Load Regulation testing is detailed here.

Hold-Up Time

Our hold-up time tests are described in detail here.

The hold-up time we measured is over 17ms, and the power-good signal is accurate.

Inrush Current

For details on our inrush current testing, please click here.

Inrush current is low with both voltage inputs.

Load Regulation And Efficiency Measurements

The first set of tests reveals the stability of the voltage rails and the RM850x’s efficiency. The applied load equals (approximately) 10 to 110 percent of the PSU's maximum load in increments of 10 percentage points.

We conducted two additional tests. During the first, we stressed the two minor rails (5V and 3.3V) with a high load, while the load at +12V was only 0.1A. This test reveals whether a PSU is compatible with Intel's C6/C7 sleep states or not. In the second test, we determined the maximum load the +12V rail could handle with minimal load on the minor rails.

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Test #12V5V3.3V5VSBDC/AC (Watts)EfficiencyFan SpeedPSU NoiseTemps (In/Out)PF/AC Volts
15.186A1.984A1.991A0.996A84.77386.891%0 RPM<6.0 dB(A)48.80°C0.980
211.397A2.973A2.988A1.196A169.67890.062%0 RPM<6.0 dB(A)49.70°C0.990
317.965A3.477A3.502A1.396A254.87591.367%0 RPM<6.0 dB(A)50.95°C0.994
424.537A3.975A3.992A1.601A339.76591.193%610 RPM10.2 dB(A)40.46°C0.990
530.782A4.974A4.996A1.801A424.68890.854%610 RPM10.2 dB(A)40.66°C0.990
637.033A5.975A5.999A2.006A509.68090.322%610 RPM10.2 dB(A)41.59°C0.991
743.285A6.977A7.004A2.205A594.65889.629%633 RPM10.9 dB(A)43.15°C0.993
849.544A7.970A8.011A2.411A679.56088.701%902 RPM23.2 dB(A)44.31°C0.994
956.244A8.474A8.533A2.410A764.68387.790%1130 RPM30.4 dB(A)45.39°C0.995
1062.684A8.980A9.022A3.022A849.43186.877%1330 RPM35.1 dB(A)46.03°C0.996
1169.730A8.981A9.029A3.025A934.34085.807%1450 RPM37.2 dB(A)46.85°C0.996
CL10.099A18.029A18.001A0.004A151.42181.633%785 RPM18.1 dB(A)44.11°C0.991
CL270.788A1.002A1.001A1.002A871.70487.227%1320 RPM33.8 dB(A)45.76°C0.996

Load regulation on all of the rails is tight, while the efficiency levels with 20% and 50% load satisfy the 80 PLUS Gold program's requirements. Under full load, the RM850x V2 achieves close to 87% efficiency, despite the high ambient temperature we test at. Finally, the PSU's noise is kept low until we apply 80% of its rated load. Even then, noise output under full load isn't bad at all.

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Contributing Editor

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

  • parkerygc8
    Sweet, first review of this I've seen. Thanks.
  • leclod
    I didn't go into detail, but I wonder what's the use of that Gold PSU when there's a Seasonic Focus Plus Platinum 750 for a similar price ?
  • Aris_Mp
    Gold, Platinum, it doesn't really matter at this efficiency point. What matters the most, in my opinion at least, is noise output now besides the basic (reliability and overall performance).
  • powernod
    At last some scoring at the review conclusion!! I always considered the lack of score as Tom's greater weakness about their reviews !!