Between the RM1200x SHIFT and RM850e (2023), the RM1200x SHIFT comes out ahead in wattage and warranty, while the RM850e (2023) wins on several specs. Overall, the RM1200x SHIFT scores 77.5 and the RM850e (2023) scores 61.1 on our Mars Score.
Which should you buy?
The RM1200x SHIFT is the clear pick on raw spec strength, leading by 16.4 points on the Mars Score. The margin is wide enough that the underdog only makes sense if its individual strengths line up with what you specifically need.
Pick the RM1200x SHIFT if you care most about wattage and warranty. The biggest gaps in its favor are wattage, warranty.
The RM850e (2023) similarly doesn't carry a headline advantage on the popular specs — look at the full table for category-specific deltas.
Both ship with comparable efficiency, modular, atx 3.0 / 12vhpwr, so those specs don't separate the two — focus on the differences below.
Bottom line: the RM1200x SHIFT is the safer default. The other model is the right choice only when its specific advantages line up with your priorities.
Why Corsair - RM1200x SHIFT wins
- ▲Wattage — 41.18% more. 1200 W vs 850 W.
- ▲Warranty — 3.00 yrs more. 10 vs 7.
Why Corsair - RM850e (2023) wins
- No decisive advantages.
Spec comparison
Spec
| Spec | Corsair - RM1200x SHIFT | Corsair - RM850e (2023) |
|---|---|---|
| Wattage | 1200 Wlead | 850 W |
| Efficiency | 80+ Gold | 80+ Gold |
| Form factor | ATX | ATX |
Features
| Spec | Corsair - RM1200x SHIFT | Corsair - RM850e (2023) |
|---|---|---|
| Modular | full | full |
| ATX 3.0 / 12VHPWR | true | true |
| Warranty | 10 yrslead | 7 yrs |
Spec-level deep dives
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