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Corsair RM750x PSU Review: Improving On A Classic

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 was much longer than 17ms, and the power-good signal was accurate.

Inrush Current

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

Observed inrush current was low with both voltage inputs.

Load Regulation And Efficiency Measurements

The first set of tests reveals the stability of the voltage rails and the RM750x’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.

Test #12V5V3.3V5VSBDC/AC (Watts)EfficiencyFan SpeedPSU NoiseTemps (In/Out)PF/AC Volts
14.364A1.984A1.999A0.997A74.79285.255%0 RPM<6.0 dB(A)48.26°C0.975
29.760A2.979A2.999A1.196A149.79589.711%0 RPM<6.0 dB(A)48.86°C0.989
315.501A3.486A3.516A1.401A224.92690.670%610 RPM10.2 dB(A)39.44°C0.993
421.245A3.983A4.003A1.601A299.79791.050%610 RPM10.2 dB(A)40.29°C0.993
526.662A4.977A5.007A1.804A374.80390.801%610 RPM10.2 dB(A)41.59°C0.991
632.076A5.976A6.018A2.006A449.68690.349%610 RPM10.2 dB(A)42.31°C0.992
737.502A6.982A7.026A2.209A524.68789.778%610 RPM10.2 dB(A)42.88°C0.993
842.937A7.975A8.037A2.411A599.62689.081%714 RPM16.5 dB(A)43.85°C0.994
948.801A8.480A8.560A2.412A674.64588.343%888 RPM22.7 dB(A)44.75°C0.995
1054.422A8.987A9.057A3.028A749.58287.520%1119 RPM30.0 dB(A)45.99°C0.995
1160.639A8.994A9.062A3.030A824.43686.724%1310 RPM34.8 dB(A)46.76°C0.996
CL10.100A18.029A18.002A0.005A151.02781.669%785 RPM18.1 dB(A)42.71°C0.992
CL262.457A1.002A1.003A1.002A771.04688.047%1116 RPM29.7 dB(A)44.99°C0.995

The RM750x's load regulation at +12V wasn't as tight as Seasonic's SSR-750FX, but it still landed within 0.6%. The minor rails performed equally well. And the 5VSB rail stayed within 2%, so it easily took the lead from the SSR-750FX.

The RM750x satisfied all 80 PLUS Gold requirements, despite the increased temperatures that we applied. At the same time, its fan spun slowly up through the ninth test. Even during our full load and overload tests, the PSU remained quiet. For comparison, the SSR-750FX under full load at 46°C generated 45.2 dB(A), while the RM750x was at 30 dB(A). That difference is huge; for every 3 dB(A), the sound intensity or acoustic power doubles. Meanwhile, the perceived volume (relative loudness) doubles for most of us with every 10 dB(A) increase. To be sure, the RM750x is one of the quietest 750W PSUs available. The best part is that this generalization still applies under highly stressful environmental conditions.

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Aris Mpitziopoulos
Contributing Editor

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

  • Dark Lord of Tech
    Excellent. Thanks!
  • Co BIY
    video has sound but no picture for me ?
  • joedavies87
    I bought one last year and did not realize that I would need two EPS cables for future builds. Moved to EVGA. Corsair was too late.