Researched, not hands-on tested.How we review ›
all judged against power supplies at a similar priceThe be quiet! Pure Power 12 M 850W scores 7.7/10 overall, ahead of the Corsair RM1000e (2025) RMe Series Fully Modular ATX 3.1 Power Supply at 7.2/10.
The be quiet! Pure Power 12 M 850W leads on cabling and connectors and warranty.
The Corsair RM1000e (2025) RMe Series Fully Modular ATX 3.1 Power Supply leads on efficiency.
They score the same on quality and protections and noise.
The biggest difference is warranty, where the be quiet! Pure Power 12 M 850W scores 10/10 to the Corsair RM1000e (2025) RMe Series Fully Modular ATX 3.1 Power Supply's 7/10.
This is an 850 W fully modular ATX 3.0 power supply for builders who want a quiet PC with a modern GPU connector. It suits gaming and general-purpose desktops that will rarely sit near full load. It is a weaker fit for anyone who wants a fan that stops entirely at idle.
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The RM1000e suits builders who want a 1000W ATX 3.1 power supply for a modern high-end graphics card. It fits people who care about low noise at everyday loads and want a native 12V-2x6 cable in the box. It is less suited to buyers who want premium internal components or a generous cable bundle.
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| Criterion | Weight | be quiet! Pure Power 12 M 850W | Corsair RM1000e (2025) RMe Series Fully Modular ATX 3.1 Power Supply |
|---|---|---|---|
| Quality and protections | 30% | 7/10 | 7/10 |
| Efficiency | 20% | 7/10 | 8/10 |
| Cabling and connectors | 20% | 8/10 | 7/10 |
| Noise | 15% | 7/10 | 7/10 |
| Warranty | 15% | 10/10 | 7/10 |
| Overall | 7.7/10 | 7.2/10 |
| Spec | be quiet! Pure Power 12 M 850W | Corsair RM1000e (2025) RMe Series Fully Modular ATX 3.1 Power Supply |
|---|---|---|
| Rated output (W) | 850 W continuous, 900 W peak; 850 W combined 12V output, 600 W combined 12VHPWR | 1000 W rated continuous output; +12V rail 83.3 A; +3.3V and +5V 150 W each; +5VSB 15 W |
| Efficiency rating (80 Plus or Cybenetics) | 80 PLUS Gold; up to 93.2% (manufacturer); Cybenetics [115V] Platinum rating, 89–91% | 80 PLUS Gold and Cybenetics Gold per Corsair; Hardware Busters measured Cybenetics Platinum (89.483% at 115 V, 91.576% at 230 V) |
| Form factor (ATX or SFX) and ATX 3.x / PCIe 5.x support | ATX 3.0; PCIe 5.1 compatible | ATX, 140 x 150 x 86 mm; ATX 3.1 certified; PCIe 5.1 compliant |
| Modular cabling (fully, semi or non-modular) | Fully modular | Fully modular |
| Graphics card connectors (12V-2x6 / 12VHPWR and PCIe 8-pin count) | One 12VHPWR (600 W); four PCIe 6+2-pin; one P8 and one P4+4 CPU; six SATA; two PATA | One native 12V-2x6 cable included; 1x 24-pin ATX, 2x EPS 8-pin, 7x SATA, 4x PATA; PCIe 8-pin count disputed across sources (2 to 6) |
| Fan size and zero-fan mode | One 120 mm rifle bearing fan, max 2000 rpm; no zero-fan mode | 120 mm rifle-bearing fan with zero-RPM mode (fan off at low and moderate loads, per Corsair) |
| Warranty (years) | 10 years | 7 years |
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