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Corsair

CORSAIR RM850x ATX 3.1 PCIe 5.1 Ready Fully Modular 850W Power Supply – Low-Noise, Cybenetics Gold Efficiency, Native 12V-2x6 Connector – Black

Based on 206 reviews
Condition: New
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$139.99
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Availability: In Stock.
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Arrives Thursday, Nov 5
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At a glance

Condition
New
Style
RMx (2024) - ATX 3.1
Size
850W
Model
CP-9020270-NA/AM
Dimensions
2.3 x 3.39 x 5.91 in
Weight
3.9 lb
Connector Type
ATX
Warranty
10 Year Manufacturer
Works with
Monitor

Features 5

  • 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.

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.

Specs 22

Model Name RM850x
Brand Corsair
Connector Type ATX
Output Wattage 850 watts
Form Factor ATX
Wattage 850 watts
Cooling Method Fan
Item dimensions L x W x H 2.3 x 3.39 x 5.91 inches

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If you place your order now, the estimated arrival date for this product is: Thursday, Nov 5

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Top Amazon Reviews

Excellent power supply for new build.
Style: RMx (2024) - ATX 3.1 Size: 850W
Perfect this time. Building two pc's and this is running 7800x3d, rx7800xt, 32gb ram, msi tomahawk x870. No issues power stays under 50% threshold unless gaming but never good above ~65% Only issue is I ordered two, first one that was white was used and didn't not have the adjustable fan. But the black one came sealed everything in bags ... show more
Reviewed in the United States on May 9, 2026 by Kathryne
Quality
Style: RMx (2024) - ATX 3.1 Size: 850W
I've built my own desktop computer for the last thirty years and have used different types of Power Supplies. Modular is nice because it keeps down the clutter in the case which helps with better air flow. This specific RM850x is clearly labeled and the cords are type IV which is nice. Unlike so many of the lesser watt power supplies, it came with 3 PCle cords. It is low-noise and runs cool. Works great. ... show more
Reviewed in the United States on June 4, 2026 by TS Shifflet
Excellent product! zero complains!
Style: RMx (2024) - ATX 3.1 Size: 850W
Working perfectly, I'm not using 12v pin connector yet I prefer to use normal connectors with Nvidia adapter.
Reviewed in the United States on May 22, 2026 by Excelente funciona al cien
Unleash Power and Silence: Corsair RM850x (2021) Power Supply Review
I recently purchased the Corsair RM850x (2021) Fully Modular ATX Power Supply, and I must say, I am extremely impressed with its performance and features. Corsair has always been known for delivering high-quality power supplies, and the RM850x is no exception. Here's my review of this remarkable power supply. First and foremost, the efficiency of the RM850x is outstanding. With its 80 PLUS Gold certification, it delivers excellent power efficiency, ensuring that my system consumes less energy and runs cooler. This not only helps in reducing electricity bills but also contributes to the overall longevity and reliability of my system. The fully modular design of the RM850x is a game-changer. It allows for easy cable management, as I can connect only the cables I need and keep the rest neatly stored away. This not only enhances the aesthetics of my build but also improves airflow within the case. The modular design also makes installation a breeze, as I can effortlessly connect the required cables without any clutter or hassle. One of the standout features of this power supply is its low-noise fan. The fan operates silently under regular loads, and I barely notice its presence. It only kicks in when the system is under heavy load, and even then, the noise levels are impressively low. The Zero RPM fan mode is particularly noteworthy, as it ensures complete silence during idle or low-power usage scenarios. This is a great feature for those who prefer a quiet computing experience. The build quality of the RM850x is top-notch. The unit feels solid and durable, and the black finish gives it a sleek and premium look. The cables provided are of high quality and have a premium feel as well. The power supply comes with all the necessary protections, including over-voltage, under-voltage, over-power, over-temperature, and short-circuit protection, ensuring the safety of my components. In terms of power delivery, the RM850x handles my system with ease. It provides ample power for my high-end components, including a demanding CPU and a high-performance graphics card. The voltage regulation is excellent, and I have not encountered any stability issues or power-related problems since installing this power supply. One minor drawback of the RM850x is its size. It's a bit larger than some other power supplies on the market, so it might not fit into smaller PC cases. However, in most standard ATX cases, this should not be an issue. Overall, the Corsair RM850x (2021) Fully Modular ATX Power Supply is an exceptional product that delivers on all fronts. Its efficiency, modular design, low-noise fan, and solid build quality make it a reliable choice for any PC enthusiast or gamer. With its impressive performance and thoughtful features, the RM850x is definitely worth the investment for those looking for a high-quality power supply to power their systems. I highly recommend the Corsair RM850x to anyone in need of a powerful, efficient, and silent power supply for their PC build. Corsair has once again raised the bar with this outstanding product. ... show more
Reviewed in the United States on July 14, 2023 by Tanner Henry
Well made and great support
I originally bought this for a browsing only PC and it worked perfectly. Modular connections and the wires that came with were perfect. I had to buy an extension to get to the Motherboard which was on the opposite side! Wish they included that. But it was just few $. Unit itself worked from get go. The fan noise was barely present! If you have nice ventilation, especially you have bottom clearance for air circulation, you shouldnt see the fan spinning much. Lets talk about support. I switched this unit for 1200W (same brand) as I had to upgrade my graphics card and add few HDD. Kept it in its box and after 6 months, when I put it to a new MB/ATX, it wont power up!! Go figure! Probably a faulty unit? Contacted Corsair via phone/email and after few initial hiccups (once their Tech Support got involved) they asked for few pictures, videos and RMA was triggered! Shipped the unit with their label and my new one is enroute! After googling I found out their 2021 model had some such failures for other people. I would still recommend this model, but get the latest one. Whats better than the best PSU, you ask? - Best Customer Support & RMA process. Anyone can say 50 years guarantee, but to stand behind that and replace as promised, thats the brand you should buy. ... show more
Reviewed in the United States on May 8, 2023 by BV
Energy Efficiency and Noise Level
This is the first PSU I ever bought for a PC, and first time installing one in a new case to move my build over from an old. My old PSU was one that came with my pre-built PC which was 500w. It started making some grinding and humming noises for a while and I also upgraded my cooling method for my CPU. I originally had a Thermalake CPU Cooler which I hated because it always got so hot. But I had to upgrade my PSU because my old one was not giving enough power. My RGB Fans and my Liquid Cooler RGB Lights would either dim or turn completely off and sometimes the PSU would get even louder like it was working a lot harder to keep the power flowing which caused a lot of performance issues. I. Love. Everything about this PSU, it's so much quieter, my computer is performing like new again, and all of my lights are staying on with no issue. I took online advice and made sure not to go cheap with this kind of thing because one cheap psu, if it's bad, it can go from cheap to expensive if you know what I mean. Your entire PC can fry which would make every component unsalvagable which means replacing the entire thing! My old PSU has been making the noises at least for over a year, I didn't think anything of it. I kept up with cleaning and maintaining it every 3 to 6 months to make sure dust never accumulated enough to cause issues. I'm still fairly new to this PC building thing but as far as my experience with this PSU so far, it's great, it's quiet, and it made my pc performance so much better. Take the advice like I did, don't go cheap with something like this. You won't regret it. The heart of your pc deserves the best for its lifespan. ... show more
Reviewed in the United States on August 15, 2022 by Kindle Customer
Great - but no eco mode switch
I bought the RM850x because of i) its high-quality clean power (verified by 3d party reviews), ii) reasonable price, iii) large number of cable ports, and iv) support from Corsair. I had been buying SuperFlower or Seasonic made PSU’s from EVGA but given events of the last year I’m not sure EVGA will remain in business for the next 10 years to support a warranty. My only real gripe is that there is no selection switch for the fan zero-rpm eco mode. Heat is the enemy of electrical component longevity; a ML fan is virtually silent at low rpm and I’d rather have it always on. However, it seems the big players in the industry would rather dumb-down the marketing of PSU’s to focus primarily on quietness and efficiency. The in-cable capacitors can be a minor annoyance; but if they are responsible for the very low ripple then I am happy to have them. Lastly, for something marketed as a premium product the packaging/accessories were rather cheap. Weak box and interior protection, no cable bag, no start-up test plug, and no manual. Makes me wonder where else Corsair cut corners on this product that I can’t see. But overall, I’m happy with the purchase and would recommend this product. ... show more
Reviewed in the United States on July 18, 2023 by Mike
Exactly the right amount of power
I was going to buy a 1,000 watt unit, but it would have been completely unnecessary. This replaces an older model of the same brand and wattage that outlived its warranty by several years. After researching reviews, I knew this would be perfect. And probably last another 10 years or so. Flawless installation. I used the provided power cable that came with it instead of reusing the old one because this was rated for a higher temperature. In case I happen to have this near my stove or something. I love the fully modular design. The older power supply had the motherboard cables permanently attached. But it was easier to route the new cables since I could attach them in any order. It is a great feeling to hook everything up, and the computer fires up with no trouble! I'm a big brand fan. ... show more
Reviewed in the United States on April 30, 2024 by redguru
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