# CORSAIR RM850 (2021) 850W Fully Modular Power Supply

> Corsair Serie RM (2021) summary. The Corsair RM850 (2021) is an 850W fully modular PSU with 80 PLUS Gold certification, 135mm low-noise fan, Zero RPM mode, and 10-year warranty.

Tags: 電源ユニット, 850w, 80plusgold
Source: https://www.amazon.co.jp/dp/B093NQKFGC
Article page: https://web-autoai.com/articles/corsair-serie-rm-2021?lang=en

Prices and ratings change over time — check the article page for the current values.

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This article covers Corsair Serie RM (2021).
The Corsair RM850 (2021) is an 850W fully modular power supply with 80 PLUS Gold certification. It balances quiet operation and stable power delivery, making it an excellent choice for mid-range to high-end gaming PCs and workstations. Its 135mm low-noise fan features a Zero RPM mode that stops the fan under light loads for near-silent operation. The fully modular cable design allows you to connect only the cables you need, improving case airflow and simplifying assembly. This unit sits in the mid-high tier of the PSU market, favored by DIY builders who prioritize reliability and noise control.
This PSU conforms to the standard ATX form factor and fits most ATX cases without issues. It provides two EPS12V CPU connectors and four PCIe 6+2 pin connectors, supporting high-end CPUs and mid-range to high-end GPUs simultaneously. Included are nine SATA power cables and four peripheral (Molex) connectors for multiple drives. The 24-pin main connector and 8-pin (4+4) CPU connector use high-quality capacitors to ensure stable power. It is compatible with all ATX motherboards and common power requirements.
Check the retailer's page for the latest price. It comes with a 10-year warranty, underscoring Corsair’s confidence in its durability. With a total power capacity of 850W and 80 PLUS Gold efficiency (≈90% at 50% load), this unit is a reliable choice for sustained high-performance builds. Its market position is mid-high tier, known for quiet operation and long-term stability.
For high-end gaming PCs combining an RTX 4070 Super or above GPU with a Ryzen 7 or Core i7 CPU, the RM850 provides ample headroom. Creative professionals who need a silent workstation will appreciate the Zero RPM mode for fanless operation at idle. Beginners building their first PC also benefit from the fully modular cables, making cable management in compact mid-tower cases much easier.

## Things to Consider
At 850W, this PSU may be overkill for entry-level or office builds; consider a lower-wattage unit if you don't plan to run high-power components. Its ATX size may not fit smaller cases like ITX or some MicroATX cases without careful measurement. Competitors such as the Seasonic Focus GX-850 and be quiet! Pure Power 11 FM 850W offer similar efficiency and noise levels, but the RM850's 10-year warranty stands out. Note that it lacks a native 12VHPWR connector, so an adapter is needed for RTX 40-series cards that require it.

### Product Disclosure (Amazon)
- Manufacturer: CORSAIR
- Seller: よろず本舗 -Aiseki- ／ YorozuHompo Aiseki
- ASIN: B093NQKFGC
- Note: This article covers a manufacturer-made product based on Amazon listing details.