What is the Best 600W+ PSU?

Corsair Professional Series HX650 Review

Manufacturer: Corsair
UK price (as reviewed): £88.04 (inc VAT)
US price (as reviewed): $119.99 (ex tax)

The Corsair Professional Series HX650 resides in the middle of the company’s large range of PSUs and attempts to offer consistent, reliable power at a reasonable price. The latter part of that claim seems to be true too – at £90, the HX650 is one of the cheaper PSUs in this half of the test. This may not initially be that remarkable until you realise that the other three PSUs we’ve tested at this price point all have captive cables, while the HX650 is modular, which gives it a distinct advantage.

The modular cables are flat too, which means that they should be easier to hide and route than the bunched, round cables present on most PSUs. Despite its keen price, the HX650 is also one of the best connected PSUs on test, with a hefty count of eight Molex and nine SATA connectors.

It also sports a pair of floppy connectors, although these have fewer uses these days. Of far more interest to bit-tech readers is the fact that the HX650 boasts four 6+2-pin PCI-E connectors, meaning that the PSU is compatible not just with single high-end graphics cards, but also has the wherewithal to power two of them.

Seasonic builds the HX650 to Corsair’s specifications and it’s equipped with one large 52A 12V rail rather than the more common multiple 12V rails. This sits alongside a 24A 3.3V rail, a 30A 5V rail, a 0.8A -12V rail and a 3A 5VSB rail.

Our Chroma testing showed the HX650 to be a solidly stable PSU, as none of the power rails dropped below the levels detailed in the ATX spec. Even at full load, the single 12V rail output a steady 11.98V, which is a great result. Efficiency was a weak spot for the HX650 though; at 50 per cent load, it only ran at 87 per cent efficiency, a figure that dropped to 85 per cent once we increased the power draw to its maximum rated level. These figures aren’t terrible, but they’re behind most of the PSUs in this group test.

Our holdup testing also revealed that the HX650 had more than the recommended 17ms holdup time on its 5V rail, but this dropped to 15ms on its 12V rail. The PSU produced a similarly middle-of-the-road result in our ripple test too, which showed a peak ripple amplitude of 28.9mV.

The Corsair HX650 is a very stable PSU at a reasonable price. Add in its modular cables and the fact that it’s armed with four 6+2-pin PCI-E cables, and you have the makings of a sturdy base on which to build a powerful PC. At this price, you obviously miss out on some goodies, though, and the HX650 takes a slight hit in terms of efficiency compared with some of the more expensive PSUs on test here. If you can live with this, though, the HX650 is a worthy purchase.