Thermaltake's Purepower RX 600W
A prescription for pure power?

With "only" a 600 watt rating, the Purepower RX could be called the baby of this round-up. It's certainly the cheapest product of the bunch, with a street price of just $105. At 600W, that translates to quite an impressive cost per watt. And there's more. Thermaltake hasn't skimped in the warranty department, delivering five years of coverage despite the RX's affordable price tag.

Surely Thermaltake has had to cut corners somewhere, and the Purepower's lack of 80 Plus certification provides the first hint. The RX is only rated for 75% efficiency, putting it at a bit of a disadvantage against the competition. Efficiency isn't everything, though, and the Purepower has other tricks up its sleeve.

A modular design is one of those tricks, and the Purepower practically looks naked without its associated cabling. This is a perfect example of just how much cable clutter can be eliminated with a modular PSU. The only leads permanently attached to the RX are 24-pin primary and 6-pin PCI Express connectors; the rest are added to suit your system's power requirements. However, should those requirements demand an 8-pin PCIe power connector, you'll have to look elsewhere. All three of the RX's PCIe power leads are of the 6-pin variety.

Like many of its rivals, the Purepower relies on a single 140mm cooling fan and ample rear-panel venting. Thermaltake always seems to make its fan grills a little thicker than others, and that may impede airflow slightly. The integrated grill does give the RX a very clean look, though.

A big bundle of modular cables rounds out the RX, and their sheathing neatly extends all the way down to each power connector. Thermaltake also throws a rubber spacer into the box that sits between the PSU and case to help reduce noise generated by vibrations.

DC regulation isn't a problem for the Purepower RX. Thermaltake keeps voltage rails consistently close to their targets across all four of our load levels.

AC ripple is very low on the RX, as well. The 12V PCIe line shows a little more AC content than the others with 25% and 50% loads, but it's still quite good.

With Thermaltake only rating the RX for 75% efficiency, these results are perhaps better than expected. The Purepower maintains at least 80% efficiency up to a 75% load, but dips to under 76% efficiency when pushed to the limit.