After a brief flirtation with multiple 12V rails, many power supply manufacturers have now returned to good, old-fashioned single 12V rails, and they appear to be getting increasingly meatier too. Cooler Master is the latest company to knock at the boundaries of the single 12V rail with its latest GX series of PSUs.
The new power supplies all come with a single 12V rail, which can account for the vast majority of their overall output. The line-up is available in 550W, 650W and 750W versions, and the latter’s hefty 12V rail is rated at 60A. That’s potentially 720W for your graphics cards and CPU, although that wouldn’t leave you a lot of power for anything else. Meanwhile, the 650W version’s 12V rail is rated at 52A for a potential total of 624W.
Cooler Master says that the PSUs have “been designed to deliver more than ample power to dual graphics card systems, no matter if you use SLI or CrossFireX.” The idea is that gamers with multiple graphics cards don’t need to worry about not having enough power.
With a single rail, there’s less danger of not getting enough current to all your cards, and 60A is a huge amount for a 750W PSU. In fact, Cooler Master is so confident in the PSUs’ capabilities that it’s kitted out the 750W PSU with four eight-pin (6+2) PCI-E power connectors, while the 650W and 550W versions have just two.
PSUs with multiple 12V rails became popular a few years ago, when Intel’s ATX 2.0 specification required a limit on the current of continuous outputs. This was later removed from version 2.3 of the ATX12V spec, resulting in today’s resurgence of PSUs with single, large 12V rails, which are ideal for powerful graphics cards and CPUs that quickly suck a 12V rail dry.
However, it’s worth noting that plenty of other PSU manufacturers are already offering similarly specified 750W PSUs, which also come with a 60A 12V rail, including Corsair, SilverStone and PC Power & Cooling.
All of the new Cooler Master PSUs come equipped with a 120mm fan, and are efficient enough to have received 80plus certification. To receive this certification, a PSU has to be 80 per cent energy-efficient at or greater 20, 50 and 100 per cent loads, with a true power factor of at least 0.9. The PSUs also come with a five-year warranty.