Find similar products here

Corsair RM850 850W Fully Modular ATX 80 PLUS Gold Power Supply

Price match guranteePrice match guarantee

We can price match this item if found elsewhere. Call us on:

0333 400 9500

Quoting product code: A59LW


About this product


Product overview

• 850W of continuous power gives you substantial headroom for overclocking, running multiple graphics cards and future upgrades
• ATX form factor allows the power supply to be connected to almost any motherboard and fits in most standard cases
• Fully modular design means you only use only the cables you require for easy builds with the best airflow
• Produces 23dBA at full load for an almost silent computing experience
• 92% efficient with a 80 PLUS gold rating, providing you with an extremely efficient power supply
• Manufacturer part number: CP-9020056-UK

Special features
• Zero RPM fan mode supplies you with near silence under light loads thanks to the built-in thermal sensor
• Corsair Link (C-Link) basic allows you to monitor fan speed and +12V current, when used with the C-Link cable and digital bridge (sold separately)

What can I run from this power supply?
If you’re looking for a power supply to power your high-end computer system and more, this 850W power supply would be a great choice for you. It will be a perfect addition to a rig that has overclocked components, multiple graphics cards (in SLI or CrossFire) and a number of other components such as fans and lights. The power supply is extremely efficient and runs very quietly thanks to its custom-designed fan and optimised blade profile. This means you can enjoy a quiet system that doesn’t waste energy. Upgrading in the future shouldn’t be an issue either – with this amount of power you’ll be free to add more components or upgrade to more energy hungry ones.

How quiet and efficient is this power supply?
Carrying an 80 PLUS gold efficiency rating, this power supply is approximately 92% efficient under various loads. This means that roughly 8% of the electrical energy it is pulling will be emitted as heat. Under a full load this power supply produces 23dBA of noise, which makes the fan almost inaudible. With the zero RPM fan mode, the fan won’t operate when under low to medium loads. Under this environment the thermal sensor will automatically control the fan speed to keep itself cool without generating extra noise. So you get a nearly silent power supply, until you really push it.

How does the fully modular design benefit me?
This power supply’s fully modular design gives you full flexibility, allowing you to only use the cables that are needed to power various components in your computer system. Through this extra flexibility you can move cables around to improve not only the aesthetic look of your case, but airflow too. Being fully modular also means that you can easily swap this power supply for a similar fully modular power supply, without having to re-do your cable management. Additionally, the flat low-profile modular cables make installation and cable management easy.

What can I do with Corsair Link basic?
Through the use of the C-Link connector and Corsair digital bridge (sold separately) you can use the C-Link program to manage fan speeds and +12V current output. Using this program you can change when the fan starts to spin – for example, you could set the fan to spin when under medium loads (despite the default meaning it doesn’t spin under medium and light loads).

Rated 5 out of 5 by from Silent Quality One of the best psu's i have bought in the last few years, super silent, you hardly know it is running, as it only spins up when needed,Superb value for money
Date published: 2015-01-07
  • y_2017, m_10, d_22, h_22
  • bvseo_bulk, prod_bvrr, vn_bulk_2.0.3
  • cp_1, bvpage1
  • co_hasreviews, tv_0, tr_1
  • loc_en_GB, sid_A59LW, prod, sort_[SortEntry(order=RELEVANCE, direction=DESCENDING)]
  • clientName_maplin-en_gb


Brand Corsair
Model number RM850
Modular type Fully Modular
Form factor ATX
Localisation United Kingdom
Colour Black
Peak power output 935 W
Sustained power output 850 W
Operation temperature 40°C
MTBF 100,000 hours
Single or multi rail Single
Input voltage 100 to 240 V
Input current 5 A to 10 A
Input frequency range 47 to 63 Hz
Power factor correction (PFC) Active
Output +12V (A) 70.8 A
Over voltage protection Yes
Under voltage protection Yes
Over current protection Yes
Efficiency and standards
Efficiency 92%
80 PLUS certification Gold
Safety certificates CE, ROHS
Compliant standards CB, TUV, FCC Class B, cUL, CCC
Cooling system 1 x 140 mm fan
Noise <23 dBA
Number of connections
20+4 pin main connectors 1
4-pin 12V connectors 1
SATA connectors 10
4-pin Molex (peripheral) connectors 8
6-pin PCI-e connectors 6
Floppy drive connectors 1
Other 1 x Corsair Link (C-Link) port
Width 150 mm
Depth 180 mm
Height 86 mm
Weight 3160 g
Manufacturer warranty 5 years
Package contents
RM850 power supply
Power cord
Modular cable pack
Accessory bag with mounting hardware, cable ties, and case badge

Is this suitable for gaming PC, using I5 quad core processor on ASUS maxi us VII ranger motherboard?

Asked by: Sea rider
I am pleased to advise the product you mentioned will do exactly what you require.
Answered by: Les
Date published: 2016-01-05

Is this ATX size?

Asked by: Phil
I am pleased to advise the product you mentioned will do exactly what you require.
Answered by: Dominic
Date published: 2015-11-27

Is this fully ATX compliant? If so, does that mean the screws and fittings will be the same as my existing ATX case and PSU?

Asked by: mick129
I am pleased to advise the product you mentioned will do exactly what you require.
Answered by: Dominic
Date published: 2015-09-08

Can this power 2x Asus GeForce Titan X 12288MB GDDR5 PCI-Express Graphics Card (GTXTITANX-12GD5) that both need a 6x &amp; 8x Pin connectors drawing 225watt for each card?

Asked by: Lee5580
Yes the product would support this. A Titan X 12GB card has a max power consumption of 300w (600w for x2). The cards themselves require an 8pin and a 6pin PCIe power connector, which this power supply can supply.
Answered by: DaveB
Date published: 2015-07-17
  • y_2017, m_10, d_22, h_22CST
  • bvseo_bulk, prod_bvqa, vn_bulk_2.0.3
  • cp_1, bvpage1
  • co_hasquestionsanswers, tq_4
  • loc_en_GB, sid_A59LW, prod, sort_[SortEntry(order=LAST_APPROVED_ANSWER_SUBMISSION_TIME, direction=DESCENDING)]
  • clientName_maplin-en_gb