Seasonic X900

Looking at the Seasonic X900, we enter the realms of redundancy. Its 900W output is considerable overkill unless you’re building a real behemoth of a system with multiple graphics cards and multiple physical processors.

Seasonic includes four PCI Express power connectors in case you want to do just that. But the real sense behind picking a supply this powerful is that components run more stably and more efficiently when they’re running well within their capabilities.

When we tested it at 50% load, the X900 achieved a creditable 86.2% efficiency and warmed up to just 25°C. At maximum load, its efficiency fell to 81.6%.

Naturally, though, you pay for the extra power. $289 isn’t pocket money, and on a cents-per-watt calculation it would be an expensive choice even if you needed the full 900W.

Its warranty is short, too, at just one year – with the exception of the Akasa, all the rest offer three or even five years.

• 
  PC Power & Cooling Silencer 750W
• 
  Akasa Powerpax 400W
• 
  FSP Everest 1010
• - Recommended -
  Cooler Master Real Power M700
• 
  Corsair HX 620W
• 
  Gigabyte Odin GT 550W
• 
  Enermax Modu82+ 525W