Seasonic S12-600

Verdict: Everything a high-end PSU should be - powerful, stable, efficient and quiet

Externally, the S12-600 is almost identical to the S12-500.

As the name suggests, the S12-600 is rated at 600W, spread over four primary rails. The 3.3V and 5V rails are each rated at 30A each, and the pair of all-important 12V rails at 18A each. This is arguably a better design than the FSP FX600-80GLN, which has four weaker 12V rails. Six Molex, two FDD, two S-ATA and two PCI-E connectors are supplied, and, unlike many dual PCI-E power supplies, the S12-600 is Nvidia SLI certified. It's also compatible with 20- and 24-pin motherboards; dual-CPU and dual-core CPU motherboards are also supported, thanks to the additional 8-pin EPS12V connector. The interior is cooled by a temperature-controlled 120mm fan.

Even when the full 36A was drawn from the two 12V rails, the S12-600 proved remarkably stable, outputting 12.03V and 11.6V respectively. What's more, the 120mm fan didn't spin up too much, so it's very quiet. The S12-600 is also incredibly efficient, averaging 82 per cent at full load, which means it only requires 726W from the mains to produce 593W.

With dual PCI-E outputs and dual-core CPU support, the S12-600 is remarkably well connected. But that's not all; it also has rock-solid outputs, a well-behaved 120mm fan and is amazingly efficient. So what are you waiting for? Go and buy one now.