In a Nutshell
The new Corsair RM750x offers nearly the same performance as its predecessor, but is overall a better PSU. Featuring quieter fan operation, two EPS connectors, and top-notch voltage stability, this PSU is great for building power-hungry PC builds.
After more than three years since it launched its last model, Corsair has decided to refresh its RMx power supply series this year. This series of PSUs is known for its completely modular high-end power supplies, but for today’s standards it doesn’t feature the best efficiency, which is why most of these PSUs now come with a more affordable price tag.
The updated RMx power supply series lineup consists of five models with different power outputs – 550, 650, 750, 850 and 1,000 W. All of these power supplies come with the same combination of features which includes fully modular cables, 80 PLUS Gold efficiency certificate, high-quality electronic components, and quiet cooling which involves a 135 mm fan with magneto-levitating bearing.
The cooling of the power supply is, in accordance with the target niche market, semi-passive, so that the fan is at rest until the load exceeds the limit of about 40 percent. In the case of our test 750-watt model, that limit is 300 watts, which basically guarantees that the power supply has passive cooling as long as the graphics card or processor is not under full load. The warranty for all of these PSUs is 10 years, which is another indicator of the quality of the components used (e.g. Japanese capacitors that can withstand temperatures of up to 105°C).
Corsair RM750x Specifications
|Max. DC Output||750 W|
|Efficiency||80 PLUS Gold (92%)|
|Power Specifications||+3,3 V – 20 A (150 W)|
+5 V – 20 A (100 W)
+12 V – 62,5 A (750 W)
|Form Factor||ATX12V v2.4, EPS 2.92|
The RM750x power supply is supplied with black screws for mounting in the PC case, and a set of disposable plastic ties for cable organization. The modular cables are packed in one transparent plastic bag, and the power supply is in the other, but it is additionally enveloped in a sponge cage for protection during transport.
The power supply design follows a new generation of Corsair products, such as the 4000 and 5000 series PC cases or the A500 air cooler. Here we primarily refer to the use of lattice parts with a triangle pattern. The power supply’s housing also features specifically cut edges, which actually gives it the shape of an octagon with four very large and four very small surfaces. The length of the whole PSU is 160 mm. Although Corsair states that these are compact dimensions, truly compact ATX power supplies are no longer than 140mm. Whether the length of the power supply will be a problem for you depends on what kind of PC case you intend to use, but the new RM750x is certainly not a champion in this aspect.
On the back of the power supply we have a connector for connecting to the power outlet and a power switch, but there is no button or switch to turn off the function of semi-passive cooling operation as on some competing power supplies. This isn’t a particular downside, but it’s still worth mentioning.
The offer of cables and connectors with this PSU is very good. There are two EPS cables, two PCIe cables with two 8-pin connectors each, two SATA cables with three connectors, one with four connectors, and one cable with four Molex connectors. What is problematic given the cost of the power supply is the design of the cables. The main ATX, EPS and PCIe cables are round and wrapped in a black mesh, and at the end they have integrated capacitors that further reduce their flexibility. SATA and Molex cables are flat, as usual. Speaking of cable’s performance, there are no surprises. The power supply can deliver full power via the 12V rail, while a total of 150 W is separated for the 3.3V and 5V rails.
We tested the new RM750x in a combination with our test PC based on the Intel Core i9-10850K processor with included Multi-Core Enhancement in the BIOS, 16 GB of DDR4 memory, MSI MAG Z490 TOMAHAWK motherboard, one M.2 SSD, ASUS ROG Strix GeForce RTX 3060 graphics card and four system fans, which include those mounted on the case, as well as the ones on the water cooling radiator. The stress testing was performed with the help of OCCT v8.1 application, and we measured the voltages with the Fluke 287 True-RMS multimeter in two operating modes – at rest, and when the graphics card and processor were both under full load. In the latter case, the power “pulled” from the socket was 668 W.
|Voltage (Rest)||3,291 V||5,055 V||12,013 V||60 W|
|Ripple (Rest)||1 mV||2 mV||5 mV|
|Voltage (Full Load)||3,283 V||5,047 V||11,93 V||668 W|
|Ripple (Full Load)||2 mV||2 mV||11 mV|
As you can see from the table above, the RM750x passed our test without any problems, with a very small voltage drop on the 12V rail. The AC voltage component, the so-called ripple, was also very low. In addition, the power supply was very quiet. That is, when it’s at rest, it is completely silent, under the first load level it is practically inaudible, while on the third level you can hear something more, although the noise is not intrusive, especially if you keep in mind that other cooling systems in the computer should be counted.
The third generation of the Corsair RMx series power supplies brings a new look, with which these PSUs follow the new generation of Corsair PC cases. The functional and electrical side of the story seems to have remained at the same level as with the previous generation of power supplies. In terms of performance, the Corsair has nothing to be shamed about because the tested power supply behaves great, but considering the price, a longer housing of 160 millimeters and rigid cables with integrated capacitors may cause problems for some users.
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