What is the best 400-599W PSU?

Seasonic X-560 Review

Manufacturer: Seasonic
UK price (as reviewed): £106.20 (inc VAT)
US price (as reviewed): $126.99 (ex tax)

At £106, the Seasonic X-560 is the most expensive sub-600W PSU in this group test. This places the X-560 under a certain amount of pressure to perform and justify its price tag. However, if previous Seasonic PSUs are anything to go by, we expect the X-560 to do just that.

The most immediately noticeable aspect of the X-560 is that it’s entirely modular. This necessitates a certain amount of design jiggery-pokery, as the internal PCBs and connectors you need for an entirely modular PSU are quite large. As a result, the X-560 is slightly bigger than most of the PSUs in this test – it’s 160mm long rather than 140mm. Like Enermax, Seasonic also makes the X-560 itself, rather than relying on another company.



The extra size is distinctly advantageous though; the totally modular design makes building a system around the X-560 easy, as you don’t need to fit any connectors until it’s safely seated in the case. It also means that there’s no need to have any more of the neatly braided cables in your case than you strictly need, thereby aiding airflow and cable routeing.

The X-560 includes a large number of cables too – it boasts a healthy count of five Molex connectors, eight SATA connectors and a pair of (admittedly slightly useless) floppy connectors. Also present is a pair of 6+2-pin PCI-E connectors, which is enough to power any of today’s power-hungry graphics cards.

As with the cheaper Thermaltake and Corsair PSUs, 12V power is handled by one single large rail. This is rated at a hearty 46A and can provide up to 99 per cent of the PSU’s total output on its own. Meanwhile, the 3.3V and 5V rails are both rated at 25A, with a combined maximum draw of 125W.

The X-560 was the most efficient PSU in this test, running at an awesome 92 per cent efficiency at half load and an equally impressive 90 per cent efficiency when fully loaded. Each rail stayed safely within the ATX spec, even when fully loaded for a prolonged period of time.

The X-560 also proved to be in a class of its own when it came to the ripple and holdup tests; its ripple result of 8.1mV was the best on test, and it also passed the holdup test on both the 12V and 5V rails.

This means that the X-560 will cope better with the micro power outages that most homes experience than any of the other 400W-599W PSUs on test. The fan also remained quiet during testing, only spinning up to a light hum at 100 per cent load.

These features and results combine to make the X-560 an incredibly desirable piece of kit, which will help to make any PC quiet, efficient and reliable. You pay for this luxury, of course, but the X-560 is special enough to justify the price.