Corsair RM1000x (2021) Power Supply Review

The Corsair RM1000x is one of the best Gold PSUs in this Wattage category.

Corsair RM1000x
(Image: © Tom's Hardware)

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Protection Features

Check out our PSUs 101 article to learn more about PSU protection features.

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Protection Features

Row 0 - Cell 1

OCP (Cold @ 25°C)

12V: 105A (126.05%), 11.980V
5V: 30.9A (154.5%), 4.996V
3.3V: 31.4A (157%), 3.275V
5VSB: 5.4A (180%), 4.889V

OCP (Hot @ 38°C)

12V: 105.2A (126.29%), 11.975V
5V: 30.8A (154%), 5.001V
3.3V: 31.3A (156.5%), 3.273V
5VSB: 5.3A (176.67%), 4.885V

OPP (Cold @ 26°C)

1262.25W (126.22%)

OPP (Hot @ 43°C)

1266.25W (126.63%)


✓ (127°C @ secondary side)


12V to Earth: ✓ 5V to Earth: ✓ 3.3V to Earth: ✓ 5VSB to Earth: ✓ -12V to Earth: ✓


Proper operation



Surge: MOV
Inrush: NTC Thermistor & Bypass relay

OCP at 12V and OPP are correctly set. On the other hand, the OCP triggering points are sky-high on the minor rails. They don't create any voltage regulation or ripple issues, but there is no need for such high amperage on these rails, which can wear off fast the DC-DC converters, under high operating temperatures. 

All other essential protection features are present and operate as they should. 

DC Power Sequencing

According to Intel’s most recent Power Supply Design Guide (revision 1.4), the +12V and 5V outputs must be equal to or greater than the 3.3V rail at all times. Unfortunately, Intel doesn't mention why it is so important to always keep the 3.3V rail's voltage lower than the levels of the other two outputs.

The 3.3V rail is always lower than the other two, so there is no problem here. 

Cross Load Tests

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

Load Regulation Charts

Efficiency Graph

(Image credit: Tom's Hardware)

Ripple Graphs

The lower the power supply's ripple, the more stable the system will be and less stress will also be applied to its components.

Infrared Images

We apply a half-load for 10 minutes with the PSU's top cover and cooling fan removed before taking photos with a modified FLIR E4 camera able to deliver an IR resolution of 320x240 (76,800 pixels).

The hottest part is the 12V board, which is connected to the main transformer through a pair of thick wires. 

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Contributing Editor

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

  • werther595
    I see in this article that you compare specs with the Superflower Leadex V Pro 1000W. Will there be a review of that unit coming out? Or is there one that I have missed?