PC parts / Power supplies
CORSAIRPower supply
RM850x (2024)
Released September 2024.4Press releasecorsair.com/newsroom/press-release/corsair-updates-popular-rmx-series-low-noise-power-supplies-with-atx-3-1-compliance-and-native-atx-12v-2x6-connectorRead 14 October 2026Press release dated September 10, 2024 for the 750W, 850W and 1000W RMx units. It says they are available now from the Corsair webstore and retailers. It gives no prices. Last checked 16 October 2026.
- Power
- 850W
- Efficiency
- Cybenetics Gold
- Modular cables
- Fully modular
- ATX version
- ATX 3.1
52 of 66 fields known.
At a glance
Hold-up time
Higher than 93% of other power supplies.
General
- Model numbers
- CP-9020270-NA, CP-9020270-EU, CP-9020270-UK1Maker product pagecorsair.com/us/en/p/psu/cp-9020270-na/rmx-series-rm850x-fully-modular-power-supply-cp-9020270-naRead 14 October 2026SKU CP-9020270-NA. The EU and UK units are CP-9020270-EU and CP-9020270-UK, listed on Corsair's German page and by UK retailers with the same Tech Specs. The Japan unit is CP-9020270-JP and is not stored.10Retailer pagescan.co.uk/products/850w-corsair-rmx-series-rm850x-black-fully-modular-cybenetics-gold-pcie-51-single-rail-140mm-fan-atxRead 14 October 2026Scan lists CP-9020270-UK.
- GTIN / EAN
- 840006667506, 840006667445, 8400066675448Spec databasecomparateur-gamer.fr/prix/corsair-rm850x-2024-840006667445Read 14 October 2026EAN 840006667445 with reference CP-9020270-EU.9Retailer pageebay.com/p/22074154707Read 14 October 2026eBay product page for CP-9020270-NA shows UPC 0840006667506. This is the only source for the NA code. The check digit is valid.10Retailer pagescan.co.uk/products/850w-corsair-rmx-series-rm850x-black-fully-modular-cybenetics-gold-pcie-51-single-rail-140mm-fan-atxRead 14 October 2026Scan lists manufacturer code CP-9020270-UK with GTIN 840006667544.
- Announced
- 10 September 20244Press releasecorsair.com/newsroom/press-release/corsair-updates-popular-rmx-series-low-noise-power-supplies-with-atx-3-1-compliance-and-native-atx-12v-2x6-connectorRead 14 October 2026Press release dated September 10, 2024.
- Predecessor
- Not available
- Successor
- Not available
- Launch price (US)
- $149.993Maker product pageweb.archive.org/web/20240913090852/https://www.corsair.com/us/en/p/psu/cp-9020270-na/rmx-series-rm850x-fully-modular-power-supply-cp-9020270-naRead 14 October 2026Archived copy of the Corsair US page from 2024-09-13, three days after launch. It shows a regular price of 149.99 USD with no discount, excluding sales tax. Hardware Busters gives an MSRP of 150 USD excluding VAT. TweakTown prints 169.99 USD, which is the later list price on Corsair's page today.6Reviewhwbusters.com/psus/corsair-rm850x-atx-v3-1-psu-reviewRead 14 October 2026Technical specifications: MSRP (excluding VAT) 150 USD. Review published September 14, 2024.
- Launch price (EU)
- Not available
- Markets
- Not available
- Colours
- Not available
- PCIe CEM version
- PCIe 5.11Maker product pagecorsair.com/us/en/p/psu/cp-9020270-na/rmx-series-rm850x-fully-modular-power-supply-cp-9020270-naRead 14 October 2026Feature list: ATX 3.1 compliant, supporting PCIe 5.1.
- Modular cables
- Fully modular1Maker product pagecorsair.com/us/en/p/psu/cp-9020270-na/rmx-series-rm850x-fully-modular-power-supply-cp-9020270-naRead 14 October 2026
- Built by (OEM)
- Channel Well Technology (CWT)5Measurementcybenetics.com/evaluations/psus/2399Read 14 October 2026DUT Information: OEM/ODM Channel Well Technology. Parts description: Manufacturer (OEM) CWT.6Reviewhwbusters.com/psus/corsair-rm850x-atx-v3-1-psu-reviewRead 14 October 2026Technical specifications: OEM Channel Well Technology (CWT).
Power
- Rated continuous power
- 850W1Maker product pagecorsair.com/us/en/p/psu/cp-9020270-na/rmx-series-rm850x-fully-modular-power-supply-cp-9020270-naRead 14 October 2026Tech Specs: Continuous Power W 850 Watts.
- Full power rated up to
- 50°C1Maker product pagecorsair.com/us/en/p/psu/cp-9020270-na/rmx-series-rm850x-fully-modular-power-supply-cp-9020270-naRead 14 October 2026Overview: 50 C continuous operating temperature. The press release rates the power output at a 50 C ambient temperature.4Press releasecorsair.com/newsroom/press-release/corsair-updates-popular-rmx-series-low-noise-power-supplies-with-atx-3-1-compliance-and-native-atx-12v-2x6-connectorRead 14 October 2026Rated power output at a 50 C ambient temperature.
- 12V rail design
- Single rail6Reviewhwbusters.com/psus/corsair-rm850x-atx-v3-1-psu-reviewRead 14 October 2026Technical specifications: 12V combined 850W on 1 12V rail.
- +12V max current
- 70.8A1Maker product pagecorsair.com/us/en/p/psu/cp-9020270-na/rmx-series-rm850x-fully-modular-power-supply-cp-9020270-naRead 14 October 2026Power table: +12V 70.8A, 849.6W, model RPS0197, part no. 75-005876.2Owner's manualcorsair.com/us/en/explorer/diy-builder/power-supply-units/corsair-rmx-seriesRead 14 October 2026RM850x power table: +12V 70.8A, 849.6W, model RPS0197.
- +12V max power
- 849.6W1Maker product pagecorsair.com/us/en/p/psu/cp-9020270-na/rmx-series-rm850x-fully-modular-power-supply-cp-9020270-naRead 14 October 2026Power table: +12V 70.8A, 849.6W.2Owner's manualcorsair.com/us/en/explorer/diy-builder/power-supply-units/corsair-rmx-seriesRead 14 October 2026RM850x power table: +12V 70.8A, 849.6W.
- +3.3V and +5V combined power
- 150W1Maker product pagecorsair.com/us/en/p/psu/cp-9020270-na/rmx-series-rm850x-fully-modular-power-supply-cp-9020270-naRead 14 October 2026Power table: +3.3V 20A and +5V 20A with one 150W cell.2Owner's manualcorsair.com/us/en/explorer/diy-builder/power-supply-units/corsair-rmx-seriesRead 14 October 2026RM850x power table: +3.3V 20A and +5V 20A, 150W.
- +5V standby current
- 3A1Maker product pagecorsair.com/us/en/p/psu/cp-9020270-na/rmx-series-rm850x-fully-modular-power-supply-cp-9020270-naRead 14 October 2026Power table: +5VSB 3A, 15W.2Owner's manualcorsair.com/us/en/explorer/diy-builder/power-supply-units/corsair-rmx-seriesRead 14 October 2026RM850x power table: +5Vsb 3A, 15W.
- AC input voltage
- Lowest100Highest240V1Maker product pagecorsair.com/us/en/p/psu/cp-9020270-na/rmx-series-rm850x-fully-modular-power-supply-cp-9020270-naRead 14 October 2026Power table: AC input 100-240V, input current 10A-5A, 47-63Hz.2Owner's manualcorsair.com/us/en/explorer/diy-builder/power-supply-units/corsair-rmx-seriesRead 14 October 2026Power table: AC input rating 100V-240V, input current 10A-5A, 47Hz-63Hz.
- Alternative low power mode (ALPM)
- Yes1Maker product pagecorsair.com/us/en/p/psu/cp-9020270-na/rmx-series-rm850x-fully-modular-power-supply-cp-9020270-naRead 14 October 2026Tech Specs: Modern Standby Yes. The Cybenetics report ticks ALPM compatible.5Measurementcybenetics.com/evaluations/psus/2399Read 14 October 2026Temperature and Compliance Info: ALPM (Alternative Low Power Mode) compatible, checked.
Certifications
- 80 PLUS rating
- Not available
- Cybenetics efficiency at 115V
- Cybenetics Gold5Measurementcybenetics.com/evaluations/psus/2399Read 14 October 2026Report 24PS2399A, certification ID 252399, issued Apr 1, 2024. The ETA badge shows Gold at 115V. The model name is RM850x (ATX v3.1). Corsair also says Cybenetics Gold without a voltage.
- Cybenetics efficiency at 230V
- Cybenetics Gold5Measurementcybenetics.com/evaluations/psus/2399Read 14 October 2026The ETA badge shows Gold at 230V.
- Cybenetics noise at 115V
- A1Maker product pagecorsair.com/us/en/p/psu/cp-9020270-na/rmx-series-rm850x-fully-modular-power-supply-cp-9020270-naRead 14 October 2026Tech Specs: Cybenetics Noise A, with no input voltage. The Cybenetics report shows A at both voltages. The launch press release says A+, which the report does not show.5Measurementcybenetics.com/evaluations/psus/2399Read 14 October 2026The LAMBDA badge shows A at 115V.
- Cybenetics noise at 230V
- A1Maker product pagecorsair.com/us/en/p/psu/cp-9020270-na/rmx-series-rm850x-fully-modular-power-supply-cp-9020270-naRead 14 October 2026Tech Specs: Cybenetics Noise A, with no input voltage. The Cybenetics report shows A at both voltages.5Measurementcybenetics.com/evaluations/psus/2399Read 14 October 2026The LAMBDA badge shows A at 230V.
Measured
- Average efficiency at 115V (measured)
- 88.815%5Measurementcybenetics.com/evaluations/psus/2399Read 14 October 2026Average over more than 1450 load combinations at 115V. Tested Mar 29, 2024 on sample serial A6GGA404K007EE, received Mar 14, 2024. Ambient 28-32 C. DUT note: CP-9020270 (Semi-Passive Off).
- Average efficiency at 230V (measured)
- 90.944%5Measurementcybenetics.com/evaluations/psus/2399Read 14 October 2026Average over more than 1450 load combinations at 230V.
- Light-load efficiency at 115V (measured)
- 75.825%5Measurementcybenetics.com/evaluations/psus/2399Read 14 October 2026Efficiency at 2% load (more than 500 W unit) at 115V.
- Average power factor at 115V (measured)
- 0.995Measurementcybenetics.com/evaluations/psus/2399Read 14 October 2026Average over more than 1450 load combinations at 115V.
- Noise at full load at 115V (measured)
- 30.8dB(A)5Measurementcybenetics.com/evaluations/psus/2399Read 14 October 2026Typical load tests at 115V, 100% load row: 30.8 dB(A) at 986 rpm fan speed, ambient about 30 C. At 230V it is also 30.8 dB(A) at 986 rpm.
- Standby power with no load at 115V (measured)
- 0.0179W5Measurementcybenetics.com/evaluations/psus/2399Read 14 October 2026Standby power consumption at 115V with no load on +5VSB.
- 12V ripple at full load (measured)
- 24.2mV5Measurementcybenetics.com/evaluations/psus/2399Read 14 October 2026Non-accredited measurement. 12V ripple at full load at 115V. At 230V it is 25.82 mV.
Cables and connectors
- Cables
Connector Connectors Cables Length to first plug (mm) Wire gauge Rated power (W) ATX 24-pin (20+4) 1 1 610 16-20AWG Not available CPU 8-pin (EPS, 4+4) 2 2 750 18AWG Not available PCIe 8-pin (6+2) 3 3 650 16-18AWG Not available 12V-2x6 1 1 650 Not available 600 SATA power 8 2 505 18AWG Not available 4-pin Molex 3 1 550 18AWG Not available Source1Maker product pagecorsair.com/us/en/p/psu/cp-9020270-na/rmx-series-rm850x-fully-modular-power-supply-cp-9020270-naRead 14 October 2026Cable listing: 1 ATX 24-pin 610 mm, 2 EPS 8-pin (4+4) 750 mm, 1 PCIe 12V-2x6 (12+4) 650 mm, 3 PCIe 8-pin (6+2) 650 mm, 2 SATA cables with 4 plugs each (505 mm to the first plug, 115 mm spacing, 850 mm total), 1 PATA cable with 3 plugs (550 mm to the first plug, 100 mm spacing, 750 mm total). All lengths have a tolerance of 10 mm, the PATA cable 25 mm. PATA plugs are the 4-pin Molex plugs. The page does not rate the 12V-2x6 cable. The Cybenetics report and Hardware Busters list it at 600 W. Gauges come from the Cybenetics report. The 16-24AWG range for the 12V-2x6 cable includes the thin sideband wires, so no gauge is stored for it. Cybenetics lists the SATA cable at 500 mm, which is not stored.2Owner's manualcorsair.com/us/en/explorer/diy-builder/power-supply-units/corsair-rmx-seriesRead 14 October 2026Included cables: 1x ATX 24-pin 610 mm, 2x EPS 8-pin (4+4) 750 mm, 1x PCIe 12V-2x6 (12+4) 650 mm, 3x PCIe 8-pin (6+2) 650 mm, 2x SATA with 4 plugs 850 mm, 1x PATA with 3 plugs 750 mm.5Measurementcybenetics.com/evaluations/psus/2399Read 14 October 2026Cables and Connectors table: ATX 16-20AWG, EPS 18AWG, 6+2 pin PCIe 16-18AWG, 12+2 pin PCIe (600W) 16-24AWG, SATA 18AWG and Molex 18AWG, no in-cable capacitors. The 12V-2x6 cable is listed at 650 mm.- CPU (EPS) connectors
- 2
- PCIe 8-pin connectors
- 3
- 16-pin GPU connectors
- 1
- SATA power connectors
- 8
- 4-pin Molex connectors
- 3
- Cable style
- Embossed or debossed flat1Maker product pagecorsair.com/us/en/p/psu/cp-9020270-na/rmx-series-rm850x-fully-modular-power-supply-cp-9020270-naRead 14 October 2026Cable listing: Cable Type Embossed for every cable. The Tech Specs row says Type 4.4Press releasecorsair.com/newsroom/press-release/corsair-updates-popular-rmx-series-low-noise-power-supplies-with-atx-3-1-compliance-and-native-atx-12v-2x6-connectorRead 14 October 2026Fully modular, embossed, ultra-flexible cables.6Reviewhwbusters.com/psus/corsair-rm850x-atx-v3-1-psu-reviewRead 14 October 2026Cables page: all cables are embossed.
Fan
- Fan size
- 140mm1Maker product pagecorsair.com/us/en/p/psu/cp-9020270-na/rmx-series-rm850x-fully-modular-power-supply-cp-9020270-naRead 14 October 2026Overview: 140mm low-noise fan.4Press releasecorsair.com/newsroom/press-release/corsair-updates-popular-rmx-series-low-noise-power-supplies-with-atx-3-1-compliance-and-native-atx-12v-2x6-connectorRead 14 October 2026140mm fan.5Measurementcybenetics.com/evaluations/psus/2399Read 14 October 2026Cooling: 140mm Fluid Dynamic Bearing Fan (NR140HP), 12V, 0.33A.
- Fan bearing
- Fluid dynamic (FDB)1Maker product pagecorsair.com/us/en/p/psu/cp-9020270-na/rmx-series-rm850x-fully-modular-power-supply-cp-9020270-naRead 14 October 2026Overview: a fluid dynamic bearing fan with magnetic dome structure. The Cybenetics report lists a Fluid Dynamic Bearing fan. The bearing is stored as fluid dynamic, since the maker names the dome as a structure of the fan and not as the bearing.4Press releasecorsair.com/newsroom/press-release/corsair-updates-popular-rmx-series-low-noise-power-supplies-with-atx-3-1-compliance-and-native-atx-12v-2x6-connectorRead 14 October 2026140mm fluid-dynamic bearing (FDB) fan.5Measurementcybenetics.com/evaluations/psus/2399Read 14 October 2026Cooling: Fluid Dynamic Bearing fan.
- Fan mode
- Semi-passive1Maker product pagecorsair.com/us/en/p/psu/cp-9020270-na/rmx-series-rm850x-fully-modular-power-supply-cp-9020270-naRead 14 October 2026Tech Specs: Zero RPM Mode Yes. The fan is off at low to medium loads.5Measurementcybenetics.com/evaluations/psus/2399Read 14 October 2026Semi-Passive Operation checked and selectable.
- Fan mode switch
- Not available
Protection and parts
- Protections
- Over-current (OCP), Over-voltage (OVP), Under-voltage (UVP), Over-power (OPP), Over-temperature (OTP), Short-circuit (SCP), No-load (NLO), Surge and inrush (SIP)2Owner's manualcorsair.com/us/en/explorer/diy-builder/power-supply-units/corsair-rmx-seriesRead 14 October 2026Protections section: OVP and UVP on 12V, 5V and 3.3V, OCP on 3.3V, 5V and 12V, OTP, SCP and OPP. The six maker protections are stored together with NLO and SIP from the Cybenetics tests.6Reviewhwbusters.com/psus/corsair-rm850x-atx-v3-1-psu-reviewRead 14 October 2026Protection Features page, which presents the Cybenetics protection tests: OCP, OPP, OTP, SCP, NLO, fan failure protection and SIP (surge MOV, inrush NTC thermistor and bypass relay) all shown. The page has no OVP or UVP row.
- All-Japanese capacitors
- Yes1Maker product pagecorsair.com/us/en/p/psu/cp-9020270-na/rmx-series-rm850x-fully-modular-power-supply-cp-9020270-naRead 14 October 2026Overview: 100% industrial-grade, 105 C rated Japanese electrolytic capacitors.4Press releasecorsair.com/newsroom/press-release/corsair-updates-popular-rmx-series-low-noise-power-supplies-with-atx-3-1-compliance-and-native-atx-12v-2x6-connectorRead 14 October 2026100% Japanese electrolytic capacitors.
Monitoring and lighting
We could not find any of these 4 fields. Show them
- Software monitoring
- Not available
- Software
- Not available
- Built-in power display
- Not available
- RGB lighting
- Not available
Dimensions and weight
Front and side, drawn to scale.
- Dimensions
- Width150Height86Depth160mm(5.9 × 3.4 × 6.3 in)1Maker product pagecorsair.com/us/en/p/psu/cp-9020270-na/rmx-series-rm850x-fully-modular-power-supply-cp-9020270-naRead 14 October 2026Tech Specs: 160x150x86 with no unit. The manual gives length 160 mm, width 150 mm and height 86 mm. Depth is 160 mm.2Owner's manualcorsair.com/us/en/explorer/diy-builder/power-supply-units/corsair-rmx-seriesRead 14 October 2026RM850x specifications: length 160 mm, width 150 mm, height 86 mm.
- Weight
- 1.79kg(3.9 lb)6Reviewhwbusters.com/psus/corsair-rm850x-atx-v3-1-psu-reviewRead 14 October 2026Technical specifications: 1.79 kg (3.95 lb). Corsair's 3 kg figure is not stored, since it is most likely a packed weight.7Reviewigorslab.de/en/corsair-rm850x-atx-v3-1-power-supply-2024-testRead 14 October 2026Igor's Lab copy of the Hardware Busters review, published November 6, 2024. It lists 1.79 kg and 150 x 85 x 160 mm. The maker's 86 mm height is stored.
In the box
We could not find any of these 1 fields. Show them
- In the box
- Not available
Links
- Product page
- www.corsair.com/us/en/p/psu/cp-9020270-na/rmx-series-rm850x-fully-modular-power-supply-cp-9020270-na1Maker product pagecorsair.com/us/en/p/psu/cp-9020270-na/rmx-series-rm850x-fully-modular-power-supply-cp-9020270-naRead 14 October 2026
- Spec sheet
- Not available
- Manual
- www.corsair.com/us/en/explorer/diy-builder/power-supply-units/corsair-rmx-series2Owner's manualcorsair.com/us/en/explorer/diy-builder/power-supply-units/corsair-rmx-seriesRead 14 October 2026
- EPREL registration number
- Not available
Warranty
Compare with
Pick a power supply to see both side by side. Differences are marked yellow.
Variants
Each variant lists only what differs from the specs above.
| Model number | GTIN |
|---|---|
| CP-9020270-NA | 840006667506 |
| CP-9020270-EU | 840006667445 |
| CP-9020270-UK | 840006667544 |
Sources
We read 10 sources for this power supply. The numbers match the markers in the sheet.
- Measurementcybenetics.com/evaluations/psus/2399
- Retailer pageebay.com/p/22074154707
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