Introduction

We would like to thank Corsair for supplying the review sample.

It hasn't been long since we reviewed the Corsair RM850 unit, and it is now time for its smaller brother with only 750 W capacity but all the features of the bigger unit. Those familiar with the PSU market will have probably guessed that the RM750 is today’s test subject. Constantly releasing new, to the competition intimidating models, Corsair has been very active lately, which pleases consumers because it gives them a broader range of choices. The fresh RM series is situated below HX and above TX units, offers Gold efficiency, a fully modular design, and an ultra-quiet operation. Corsair also decided to release a PSU series that focuses on producing as little noise as possible with the RM series, and they really did conduct a ton of research to make sure these new units are noise-proof. Considering the astonishing results their RM850 achieved in our tests, we can truly state Corsair’s efforts in this area to be noteworthy.

The RM series consists of six models with capacities ranging from 450 W to 1000 W. Four of these units are made by Corsair’s favorite OEM, Channel Well Technology, while the 750 W and 850 W models are made by Chicony, an OEM we haven’t come across in our reviews yet. We don’t know the exact reasons that led Corsair to Chicony for the making of the two mid-range models, but they were apparently important enough to make the switch.

The RM units use older, trustworthy analog circuits that still make them somewhat compatible with the Corsair Link software only fully utilized by the digital AXi units, but you have to get the optional Digital Bridge to monitor +12V current output and fan speed because Corsair chose not to include the Bridge in the bundle. Doing so would have raised the final price, yet some of you will appreciate saving some money while others would have preferred it if Corsair had included the Digital Bride for a small price increase.

Specifications

All RM units are 80 Plus Gold certified, and their maximum operating temperature is restricted to 40°C, tough ATX spec recommends at least 50°C. Corsair most likely didn't want to encourage users to push the unit to its limit in high ambient temperatures because of its semi-passive operation and the Chinese caps in the secondary side. All protection features are thankfully present, including OTP (Over Temperature Protection), which will save the PSU if the fan malfunctions. Speaking of the fan: It uses rifle bearings and has a diameter of 135 mm.

With a length of 18 cm, the RM 750 is large for a 750 W PSU. Still, its length won't be a problem for most ATX cases. The RM unit is also compliant with the newest ATX v2.4 spec, so it is Haswell ready, though Intel skipped over its Haswell compliance requirements with this spec to probably add them into the next. Finally, the warranty is quite long at five years, and the price is on par with offerings by the competition.


The single +12V rail is strong enough since it can deliver the unit's full power alone, which suits modern systems well as they tend to exploit this rail over all others. The minor rails are also powerful enough with 150 W maximum combined power, while the 5VSB rail is a little stronger than 2.5 A, the minimum current output for a decent PSU on this rail.

Cables & Connectors, Power Distribution

There are enough PCIe connectors for the capacity of the unit, but we would like an additional EPS connector, which should be present in a 750 W PSU, although it won't be used by the majority of users. There are enough SATA and Peripheral connectors to cover every need. However, the distance between Peripheral connectors is small and should ideally be 13-15 cm. Finally, all connectors use 18AWG gauges, which is the size ATX recommends for most PSUs.

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

Packaging

The RM750 comes in a similar package as the RM850—only the model number and some data changed. The front then has a close-up of the nicely designed fan grill, the model number, and a series of badges drawing our attention to the unit's quiet operation, Gold efficiency, semi-passive operation, and five year warranty.


Only the model number is depicted on this side, along with the descriptor "ultra-quiet PSU", which certainly holds true.


On this side, Corsair was kind enough to provide detailed information on all available connectors that equip this PSU, including their corresponding cable length.


On the rear are two graphs showing the efficiency and fan noise curves, and the power specifications table in the bottom-right corner. A QR code on top will lead you to the official product page with more information, photos, etc.

Contents

The package comes with a sleeve. It hides a sturdy cardboard box inside of which the PSU is surrounded by packing foam for ample protection. Corsair is very cautious and provides their PSUs with great packaging, which is to their own benefit since it prevents avoidable DOAs, keeping RMAs to a minimum.


The bundle includes an AC power cord, the modular cables, a set of fixing bolts, several leaflets, including the user's manual and a notification referring to the RM750's semi-passive mode. The latter notification lets inexperienced users know that there is nothing wrong with the sitting-like-a-duck fan at lower loads. Corsair should really add a fan-test mode to have users figure out whether the fan is working properly or not. Such a test mode could be engaged via a button or simply during the PSU start-up phase, by having the fan rotate for a couple seconds.