Corsair RMx Shift
The 850W I'd buy for a tidy mid-tower build, as long as your case has room for the side sockets.
- Efficiency
- 80+ Gold
- Modular
- Full
- Standard
- ATX 3
- Form factor
- ATX
- Outputs
- 750 / 850 / 1000W
The verdict
The Shift moves the cable sockets from the end of the unit to the side, so the cables point towards the back of your case. In the right case that makes for a much cleaner build, and it's why I rate it so highly.
The lab results back it up. Both current reviews found it very quiet and electrically excellent, with high build quality and a 140mm fluid dynamic bearing fan. Their only shared gripe is a protection limit on the minor rails that's set too loosely.
The catch is fit. The sockets face your side panel, so you need a few centimetres of space there. Check your case before you buy.
Corsair RMx Shift reviews
The two most detailed lab tests of the current ATX 3.1 version agree it's very quiet, well built and electrically excellent. Their one shared criticism is a loosely set protection limit on the minor rails. For most buyers, the bigger question is whether it fits their case.
Both labs agree
- Very quiet, even under heavy load. HWBustersigor'sLAB
- High efficiency across the whole load range. HWBustersigor'sLAB
- Tight voltage regulation, low ripple and a clean response to sudden load changes. HWBustersigor'sLAB
- High build quality, with a 140mm fluid dynamic bearing fan. HWBustersigor'sLAB
- Over-current protection on the minor rails is set loosely and could be tighter. HWBustersigor'sLAB
Where they differ
- Fan failure protection: HWBusters lists it as missing, igor'sLAB says it's included. HWBustersigor'sLAB
- Efficiency rating: sold as 80 Plus Gold. HWBusters notes Cybenetics rates it Platinum; igor'sLAB puts it in the upper Gold range. HWBustersigor'sLAB
Also worth knowing
- The side-mounted sockets and extra depth don't suit every case, and it costs more than many 850W rivals. igor'sLAB
Offers top performance and high build quality.RM850x Shift, ATX 3.1igor'sLAB
An investment that will pay for itself over the lifetime of the system.RM850x Shift, ATX 3.1 (2025)Tom's HardwareAugust 2024
Delivers excellent efficiency and quiet operation for those willing to settle on a compatible case.Earlier RM850x Shift sample
Tom's Hardware tested an earlier sample, so it's shown for reference and not counted. Reviews tested the 850W model.
Pick your output
- 750WMid-range builds, up to an RTX 5070 Ti class card.Check 750W price
- 850WHigh-end builds, up to an RTX 5080 class card.Check 850W price
- 1000WThe most power-hungry cards, RTX 5090 class.Check 1000W price
Sizes assume a typical processor. Check your build in the wattage guide.
Other Tier A at 850W
- undefined80+ TitaniumCheck price
- undefined80+ GoldCheck price
- undefined80+ GoldCheck price
- undefined80+ GoldCheck price
Specs
| Tier on my list | A · High-end builds |
|---|---|
| Wattages | 750W, 850W, 1000W |
| Efficiency | 80 Plus Gold |
| Modular | Fully modular |
| Standard | ATX 3 |
| Size | ATX |
| Released | 2025 |
Corsair RMx Shift questions
Will the RMx Shift fit my case?
Most mid-tower cases with a power supply shroud and cable space behind the motherboard work. Check there's a gap of a few centimetres between the power supply and the side panel for the cables to bend. Corsair engineer Jon Gerow published a list of compatible cases (April 2024).
How is the RMx Shift different from the regular RMx?
The sockets are on the side of the unit instead of the end, so cables run straight towards the back of the case. The regular RMx (2024) has end-mounted sockets and fits almost any ATX case.
Is the RMx Shift quiet?
Yes. Both current-version lab reviews found it very quiet, even under heavy load. HWBusters called it one of the quietest 850W units it has tested.
Does the RMx Shift have fan failure protection?
The reviews disagree. HWBusters lists it as missing, while igor'sLAB says it's included.
Which Corsair RMx Shift wattage should I get?
It comes in 750W, 850W, 1000W. Match it to your graphics card using the output guide above, or the calculator for your exact parts.
Can I reuse cables from my old power supply with the RMx Shift?
Use the cables that came in the box. Modular cables aren't standard between brands, or even between generations from one brand, and the wrong cable can damage your parts.