PC power supplies

It's easy to imagine that all power supplies are the same, and when you can buy a "no-name" unit for a tenner you might wonder why you'd pay anything more.

But dirt-cheap models can't always provide the advertised wattage, leading to intermittent crashes or even a complete burn-out at higher loads. They can be woefully inefficient, too, wasting as much as a third of the power they draw.

If you value the stability of your system - and want to keep electricity bills to a minimum - it makes sense to invest in a high-quality supply and let the savings on your electricity bill offset the extra cost.

See also: PC cases roundup.

This month, we've taken eight big-brand power supplies and subjected them to extensive electrical testing at 25%, 50%, 75% and 100% of their claimed capacity.

The good news is that all of them proved comfortably able to deliver the promised power levels, and all ran stably, with no rail deviating more than 3% from its proper voltage (the ATX standard allows for 5% deviation on the main rails).

We also tested for power efficiency and all achieved better than 80% - see the chart opposite for each supply's average efficiency across our tests.

But that isn't to say they're interchangeable: each has its own strengths, and there's a huge range of capacities on offer.

Click the links below to read the reviews:
Intro
Akasa PowerPax 400W
Enermax Modu82+ 525W
Gigabyte Odin GT 550W
Corsair HX 620W
Cooler Master Real Power M700 - Recommended
Seasonic X900
FSP Everest 1010
PC Power & Cooling Silencer 750W

Author: Darien Graham-Smith