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Corsair RM650 Power Supply Review: Silent and Efficient

Protection Features, DC Power Sequencing, Cross-Load Tests and Infrared Images

Protection Features

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

Protection Features
OCP12V: 68.8A (127.41%), 12.021V 5V: 29.3A (146.5%), 5.023V 3.3V: 29.6A (148%), 3.283V 5VSB: 5.1A (170%), 4.920V
OPP841.3W (129.43%)
OTP✓ (157°C @ secondary side)
SCP12V: ✓ 5V: ✓ 3.3V: ✓ 5VSB: ✓ -12V: ✓
PWR_OKProper Operation
SIPSurge: MOV Inrush: NTC Thermistor & Bypass Relay

The OCP triggering points on the minor rails are super high, and the same goes for the 5VSB rail. In no case though, the load regulations is affected, and this is the case as well, for ripple suppression.

The Over Power Protection (OPP) is appropriately set, within 130% of the PSU's capacity. Finally, there is Over Temperature Protection, and the power ok signal is accurate (and longer than 16ms).

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.

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The 3.3V rail is the last to start, so its voltage is always lower than the other two.

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

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Efficiency Chart

The 90-92% efficiency region is quite large. It would be nice, to see even a small region, with higher than 92% efficiency. 

Ripple Charts

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

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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).

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As we expected, the hottest parts are on the DC-DC converter's board, which we stressed enough with 10 Amperes of load on each of the 5V and 3.3V rails.

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