Review Corsair RM750x PSU : Improving On A Classic

The second generation Corsair RM850x power supply impresses us in our latest review, so we are relatively confident that the company's updated RM750x will be the same. As indicated by their name, the maximum capacity of 100W separates the two models. However RM750x costs $ 20 less, landed at $ 110.

Corsair RM750x V2 

Pros

•     Excellent ripple suppression
•     Quiet across its operating range
•     Solid build quality
•     Fully modular
•     2x EPS & 4x PCIe connectors
•     Smaller dimensions than its predecessor
•     10-year warranty

Cons

•     In-cable capacitors
•     Short distance between peripheral connectors
•     No fan-test button

Decision

The new RM750x is clearly a better PSU than previous versions, offering similar performance in a more compact chassis, along with a quieter fan profile. Cherry above is the inclusion of two EPS connectors, which make this PSU compatible with power-hungry platforms. If Corsair maintains a price tag below $ 110, RM750x will remain a winner in the 750W category.

The two main PSUs sport a number of changes compared to the original RMx line-up, including shallow depth measurements. In addition, the new RM750x includes a second EPS connector to support high-end CPUs, while the first gene implementations do not. Corsair went out of the way to improve the acoustic profile of RM750x, as well. As a result, the main power supply is unmatched by its competitors in our noise measurements. It should not be surprising that we recommend RM750x for fans of shopping for a quiet and crowded PSU with plenty of output capacity.

Of course, this helps that the category of the PSU 750W is very popular, touching the sweet spot at an affordable price and ample headroom for upscale hardware. That's why we think all 750W power supplies should include some EPS connectors, and why it's a shame that the original RM750x has only one. Thankfully, Corsair discusses this apparent weakness. Shallow depth is also a big issue, increasing compatibility with smaller cases.The higher efficiency levels offered by the new platform minimize the thermal load. As a result, PSU manufacturers no longer need to use a very large heat sink. There are even models that do not use sinks on all secondary sides. The old and new RMX PSU is a great example for this.Corsair's second-gen RM750x maintains the same external design, so the only way to distinguish it from its predecessor is to compare its size. The new model has a depth of 16cm, while the old one measures 18cm. However, 16mm is not enough to make the RM750x one of the shortest PSU 750W out there; Similar capacity alternatives such as Seasonic Focus Plus Gold, SilverStone Strider Gold S V2 750W, and Cooler Master V750 only 14cm.

Specifications  

• Manufacturer (OEM)    CWT
• Max. DC Output    750W
• Efficiency    80 PLUS Gold, ETA-A
• Noise    LAMBDA-A+
• Modular    ✓ (Fully)
• Intel C6/C7 Power State Support    ✓
• Operating Temperature (Continuous Full Load)    0 - 50°C
• Over Voltage Protection    ✓
• Under Voltage Protection    ✓
• Over Power Protection    ✓
• Over Current (+12V) Protection    ✗
• Over Temperature Protection    ✓
• Short Circuit Protection    ✓
• Surge Protection    ✓
• Inrush Current Protection    ✓
• Fan Failure Protection    ✗
• No Load Operation    ✓
• Cooling    135mm Rifle Bearing Fan (NR135L)
• Semi-Passive Operation    ✓
• Dimensions (WxHxD)    150 x 86 x 162mm
• Weight    1.61kg (3.55lb)
• Form Factor    ATX12V v2.4, EPS 2.92 

 RM750x achieves 80 PLUS Gold and ETA-A efficiency. Cybenetics also certifies LAMBDA-A +. The overall noise output of about 15 dB (A) makes the RM750x one of the most secured 750W PSUs available. Although Seasonic Focus Plus Gold and EVGA's 750 G3 are strong competitors, none of them are lonely.

The full Corsair feature protection feature, apart from OCP on the + 12V rails, is replaced with excess power protection on single-rail PSUs. Active cooling is handled by a 135mm fan with rifle pads.

Power Specifications  

• Rail    3.3V    5V    12V    5VSB    -12V
• Max. Power    Amps    25    25    62.5    3    0.8
• Watts    150    750    15    9.6
• Total Max. Power (W)    750 

The RM750x minor rail has a higher capacity than is required for modern PCs, while the + 12V rail can provide up to 62.5A. The Corsair 5VSB rail is quite plump for the 750W PSU.

Cables & Connectors  

• Modular Cables
• Description    Cable Count    Connector Count (Total)    Gauge    In Cable Capacitors
• ATX connector 20+4 pin (600mm)    1    1    18-20AWG    Yes
• 4+4 pin EPS12V (650mm)    2    2    18AWG    Yes
• 6+2 pin PCIe (600mm+150mm)     2    4    18AWG    Yes
• SATA (520mm+110mm+110mm)    3    9    18AWG    No
• Four-pin Molex (450mm+100mm+100mm+100mm)    2    8    18AWG    No
• FDD Adapter (+100mm)    1    1    20AWG    No
• AC Power Cord (1430mm) - C13 coupler    1    1    16AWG    - 

 Corsair provides two EPS connectors and four PCIe ones. The RM750x includes more peripheral connectors as well, and we're happy to see the company implementing eight pin-pin four pin connectors because so many peripherals use them. Our only criticism is the distance between the connectors is too small only 10 cm. We prefer 15cm, at least.

The ATX, EPS, and PCIe cables are equipped with capacitors to help reduce the ripple on the PSU output.