On our desk this week - 4

Coolermaster RealPower 550W

PSUs are never the most exciting things in the world, but a good one is nonetheless essential to your system stability. Today, we have a unit from Coolermaster that is designed to be a true 550W unit, rather than being labelled as a 550 and actually putting out much less, like some competitors.

Whirring up at around £70, the unit sports a 120mm fan on the top for cooling. Although the use of a single 120mm fan is supposed to keep things quiet in your case, we found that the fan was spinning up so fast that it was incredibly loud a great deal of the time. Regardless of power output and stability, noise is not a good thing!

The PSU has a fairly decent number of cables, although we're disappointed that they're not sleeved - these days, with so many enthusiast PSUs coming with handily sleeved wires, why would you buy one without? In total, the unit has a standard 24-pin ATX cable, a P4 cable, 1 floppy, 2 PCI-Express graphics, 6 quick-release molex and 3 SATA cables.

There is also a connector for hooking up this nifty front panel device. It is basically a volt meter, designed to show how much power your system is drawing. It's not a spot-on accurate measurement, but it's there and thereabouts.

In testing, we did find that the PSU was stable and efficient. The 5V rail stayed consistently over 5V in our torture testing. The 12V rail only dropped to 11.80V, which is an acceptable loss, and the 3.3V rail sat merrily at 3.35V for the duration too, only dipping briefly.

The RealPower lives up to its claims to be a stable, full-voltage PSU that's great for high-powered systems. Unfortunately, the fan noise and the lack of cable sleeving make this difficult to recommend when there are so many other power supplies out there in this price range.

Name: CoolerMaster RealPower 550W
Buy it from: Overclock
Cost: £70
Verdict: Good performance, but too loud and no cable sleeving make this run-of-the-mill for the price.