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Corsair RM650x PSU Review

Another Corsair PSU is in the lab, commanding our attention. We already reviewed the RM750x and RM550x, so we couldn't leave out the RM650x. It promises the same high performance as its siblings, along with super quiet operation.

Our Verdict

The RM650x is a high performance PSU featuring great build quality and a very silent operation. It is offered at a fair price and the ten-year warranty is the cherry on top. Its major problem seems to be the harsh competition from EVGA's similar priced offerings, especially the 650 P2 model.


  • Full power at 49°C
  • Ripple suppression
  • Load regulation
  • Performance with transient loads
  • Silent
  • Compact dimensions
  • Quality caps
  • Fully modular
  • Hold-up time
  • Warranty


  • Single EPS connector
  • Short distance between peripheral connectors
  • No bypass relay in the inrush current protection circuit

Corsair RM650x Power Supply Review

The most popular power supplies among enthusiasts who do their homework come from EVGA's G2 and P2 families, and Corsair's RMx and RMi line-ups. You simply cannot go wrong with any of them. At least in the U.S., those companies do battle with each other, leaving everyone else behind.

EVGA puts its trust in Super Flower, one of the best OEMs out there. Unfortunately, it looks like Super Flower is having a hard time keeping up with demand. On the other hand, Corsair cooperates closely with CWT. It also has an in-house team of PSU engineers who not only make changes to CWT's platforms, but actually help design them. We've reviewed two members of the RMx line and their results were amazing. We expect nothing less from the RM650x on our test bench today.

Like all RMx models, the RM650x is 80 PLUS Gold-certified, features fully modular cabling, and is equipped with a medium-speed rifle bearing fan. Its platform is shared with the RMi family; Corsair simply leaves off the digital interface that allows the PSU to communicate through its Link application. On top of that, the RMi units use a higher-quality FDB fan. The price difference between the RM650x and RM650i is $20 bucks, and we think that delta is justified given the higher-end unit's extras. But if you're on a tight budget and don't care much about the digital interface, you should be fine with the RM650x.


This PSU delivers its full power continuously at up to 50 °C. That fact alone means the platform is equipped with heat-tolerant components, which is important since thermal energy is a major threat to stable power. Moreover, Corsair provides a full set of protection features, including OCP for the minor rails and over-temperature protection.

Apparently, Corsair is confident enough in the RM650x to arm it with a 10-year warranty. The medium-speed rifle bearing fan is controlled by a conservative profile, and a semi-passive mode keeps the fan inactive under light and moderate loads. Finally, the PSU's physical dimensions are normal for its capacity.

Power Specifications

Max. PowerAmps25255430.8
Total Max. Power (W)650

The minor rails can provide up to 130W, which is enough for most systems. Meanwhile, the +12V rail delivers up to 54A. Taking into account the low power consumption of AMD's and Nvidia's newer GPUs, 650W should be enough for two high-end graphics cards and a potent CPU. We also think the 5VSB rail is strong enough for a mid-capacity PSU like the RM650x.

Cables And Connectors

Modular Cables
DescriptionCable CountConnector Count (Total)
ATX connector 20+4 pin (610mm)11
4+4 pin EPS12V (660mm)11
6+2 pin PCIe (600mm+150mm)24
SATA (520mm+110mm+110mm)39
Four-pin Molex (450mm+100mm+100mm+100mm)14
FDD Adapter (+100mm)11

As we noted in the RM550x review, all RMx units use Corsair's "Type 4" cables that feature capacitors on the ATX, EPS, and PCIe leads to further suppress ripple. In addition, the ATX cable has four more wires that help maintain tight load regulation. The connector count is satisfactory for this PSU, except for the single EPS connector. We think Corsair should provide a second one.

At least the Berg connector is provided as an adapter, and not fixed on a cable. It's only a shame that the adapter doesn't feature a pass-through Molex connector, so you lose one of the provided four when you attach it.

With only 10cm separating the peripheral connectors, you may have a hard time with some enclosures. Corsair should put at least 15cm between these connectors. Lastly, most of the cables employ 18-gauge wires, satisfying the ATX spec's recommendation.

Power Distribution

Since this PSU features a single +12V rail, we do not have anything to say about its power distribution.

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