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Corsair

CORSAIR RM850x Fully Modular Low-Noise ATX Power Supply – ATX 3.1 Compliant – PCIe 5.1 Support – Cybenetics Gold Efficiency – Native 12V-2x6 Connector – Black

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Style: RMx (2024) - ATX 3.1


Size: 850W


Features

  • Fully Modular: Reliable and efficient low-noise power supply with fully modular cabling, so you only have to connect the cables your system needs.
  • Cybenetics Gold-Certified: Rated for up to 91% efficiency, resulting in lower power consumption, less noise, and cooler temperatures.
  • ATX 3.1 Compliant: Compliant with the ATX 3.1 power standard from Intel, supporting PCIe 5.1 and resisting transient power spikes.
  • Native 12V-2x6 Connector: Ensures compatibility with the latest graphics cards with a direct GPU to PSU connection no adapter necessary.
  • Embossed Cables with Low-Profile Combs: Sleek, ultra-flexible embossed cables look great and make installing and connecting the RMx a breeze.

Description

CORSAIR RMx Series Fully Modular Low-Noise Power Supplies deliver quiet, dependable power with Cybenetics Gold efficiency to your PC. Fully modular, ultra-flexible embossed cables make PC builds easy, as you connect only the cables your system requires. Compliant with the ATX 3.1 power standard from Intel®, RMx PSUs have the connections needed to power today’s demanding PC hardware including a native 12V-2x6 connector. 100% Japanese 105°C-rated electrolytic capacitors deliver fantastic electrical performance, while a 140mm FDB fan provides low noise cooling. Backed by a ten-year warranty, RMx PSUs are the gold standard for many years to come.

Model Name: RMx


Brand: Corsair


Compatible Devices: Monitor


Connector Type: ATX


Output Wattage: 850 Watts


Form Factor: ATX


Wattage: 850 watts


Cooling Method: Air


Item dimensions L x W x H: 2.3 x 3.39 x 5.91 inches


Item Weight: 3.9 Pounds


Compatible Devices: Monitor


Connector Type Used on Cable: ATX


Output Wattage: 850 Watts


Form Factor: ATX


Wattage: 850 watts


Cooling Method: Air


Power Supply Design: Full Modular


Number of Fans: 1


Maximum Input Voltage: 264 Volts (AC)


Minimum Input Voltage: 100 Volts (AC)


System Bus Connector Type: ATX


Item Dimensions: 2.3 x 3.39 x 5.91 inches


Item Weight: 3.9 Pounds


Model Name: RMx


Brand: Corsair


Manufacturer: Corsair


UPC: 840006667506


Mfr Part Number: CP-9020270-NA


Model Number: CP-9020270-NA


Warranty Description: 10 Year Manufacturer


Frequently asked questions

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Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

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View our full returns policy here.

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Similar Products

Top Amazon Reviews

    • Corsair remains as reliable as ever
Style: RMx (2024) - ATX 3.1 Size: 850W
For as long as I've been building my own computers - more than twenty-five years now - I've used Corsair power supplies. I don't necessarily think they are better than any other brand, but they've never let me down, despite all my computers generally running 24/7 in dusty, sometimes humid, sometimes 90F environments. I purchased this not because my old Corsair supply failed, but because I was installing a 5070Ti and wanted higher output as a result - the 650W would have barely been suitable. Swapping supplies was dead simple; the old one slotted in place of my old RM650x, and all I needed to do is replace the old power cable from the RX470 with the newer 12V-2x6pin. I have all Cablemod Sleeved cables and debated replacing the the new 12-pin connector with a sleeved variant, but it's so flexible and clean looking I decided the Corsair one was just fine. I've been running for about three months now without any issue. Obviously not much time on a PSU but I doubt I'll have problems. As an aside, this one has a variable fan speed knob. So far as I can tell, if you leave it off it will just run in normal, automatic mode, whereas if you use the knob it will instead always run at a certain speed. I think, I'm not totally clear on it. I just keep the knob off - my system is already very quiet and I don't think I've ever heard the PSU fan turn on even with my old supply, much less this newer one. As my mobo doesn't support PCIe 5.1, I can't comment on that part of the component. I would definitely recommend this RM850x, and would recommend Corsair in general, so far as PSUs are concerned. They seem very solid and well-made, and I've never been disappointed by them in the past. ... show more
Reviewed in the United States on December 12, 2025 by AC
    • Stability, ease of use, quiet, and a well established design.
Style: RMx (2024) - ATX 3.1 Size: 850W
Bought this 850 watt unit 6 months ago and just now last week installed it. Everything went smooth, my son did most of it, no problems with cables or routing or anything. I love the feature of being able to control the fan speed. This is a well built, well known PSU. It is performing as expected, which is quiet, cool and stable. Highly recommend this unit from Corsair. ... show more
Reviewed in the United States on September 7, 2025 by doug
    • Best PSUs on the market
Style: RMx (2024) - ATX 3.1 Size: 850W
Corsair PSUs in my experience are always easy to work with. The cables are very easy to manage because they come with zip ties and braid organizers (if that is the right term for them). It is a very sleek design, and I really like the cables themselves. I have had no issues with performance, and I haven't had any issues with power to my PC. My estimated wattage is about 600, so this leaves me some room for upgrades if I want. You are definitely paying for less than you get with this, it is an extremely good investment in terms of what you get versus how much you pay. ... show more
Reviewed in the United States on July 23, 2025 by Drew Lipscomb
    • Every single feature and thing you'd ever need in a psu.
Style: RMx (2024) - ATX 3.1 Size: 850W
Review Image by Jacob Bencon
Amazing A rated power supply. Comes with any cable you'd need. I had mistakenly bought another psu with not enough ports, I assumed that the prior psu would have interchangeable eps and pcie ports. Boy was I wrong. I bought this as a replacement, and it works amazingly. If you're worried about fan noise, it has a silent mode. If you're worried about cooling, you can turn the knob on the back to increase fan speed. The fact this also comes with 3 (6+2) 8 pin pcie cables is amazing. Good job corsair engineers you made a beautiful power supply. ... show more
Reviewed in the United States on September 12, 2025 by Jacob Bencon
    • Corsair makes stable and reliable PSUs...
Style: RMx (2024) - ATX 3.1 Size: 850W
I'm not sure if Corsair PSUs can be beat at their price point. This PSU offers excellent performance at a decent price point. Great for gamers or PC users who want stable, consistent performance. Pros Sleek design Quiet operation Low ripple power Consistent voltage even under load Reliable, should last for years Excellent warranty Cons None yet ... show more
Reviewed in the United States on August 26, 2025 by Dan
    • Just what my underpowered PC needed
Style: RMx (2024) - ATX 3.1 Size: 850W
Perfect for my new computer that I underpowered and had performance issues with. Connections were easy to make with the modular cables. The inside of the chassis is much more organized, with improved airflow.
Reviewed in the United States on January 31, 2026 by Tony B.
    • It handled like a champ.
Style: RMx (2024) - ATX 3.1 Size: 850W
I bought one years ago and lightning struck my house. This power supply took a jolt and kept on working. So, I bought another one (this one, lol). These power supplies are great. Easy to setup and use. Pretty easy cable management do to it being fully modular. Its very quiet except when you adj7st the fan to high. Its not l9ud, but you can definitely tell it's moving air, lol. The nob on the back adjusts the fan speed if you want more cooling. Well worth the buy. ... show more
Reviewed in the United States on September 5, 2025 by IamKraZ
    • Powerful and Efficient
Style: RMx (2024) - ATX 3.1 Size: 850W
An incredibly powerful power supply. I found the modular cable supply very handy, especially when coming from a Thermaltake power supply. I found it to be efficient and respond well to my computer's needs. It was very easy to install. I highly recommend this power supply. I have found no issues since my install. ... show more
Reviewed in the United States on January 2, 2026 by Ninnamon12

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