80 Plus Bronze PSUs

80 Plus Bronze certifies that a power supply converts around 85% of the mains power it draws into usable output, with the rest lost as heat.

For a great many builds that is entirely sufficient. The efficiency difference between Bronze and Gold is a few percent, which on a machine used a few hours a day amounts to very little on a bill — the money is usually better spent elsewhere in the build. What Gold and above genuinely buy is a quieter fan, because less waste heat needs removing.

What matters more than the rating at this end of the market is the standard. If the build includes a modern discrete graphics card, look for ATX 3.0 or 3.1: those units are designed for the brief power spikes current GPUs produce, which is the difference between a machine that rides them out and one that shuts down under load despite adequate wattage on paper.

Sizing: integrated graphics or a modest card is comfortable on 500-650W; a mid-range card wants 650-750W.

The range covers ASRock, VIDA, Antec, Corsair, be quiet!, MSI, DeepCool, CRONUS and GameMax.