The Corsair RM1200x SHIFT and the Thermaltake Toughpower GF A3 850W are evenly matched, resulting in an objective tie across the majority of their specifications. While both units share identical performance in five key areas, the Corsair RM1200x SHIFT holds a significant lead in power capacity, offering 41% more wattage than its competitor. Conversely, the Thermaltake Toughpower GF A3 850W provides a substantial financial advantage, boasting an MSRP that is 54% better than the alternative.

Users requiring maximum power delivery for high-draw systems should prioritize the Corsair RM1200x SHIFT to utilize its superior wattage capacity. Those operating on a stricter budget who do not require the extra power overhead should select the Thermaltake Toughpower GF A3 850W to take advantage of its lower MSRP. Both power supplies offer equivalent performance in the remaining technical categories, making the choice dependent entirely on whether the user values higher output or lower cost.