The Seasonic X series 560 watt power supply is the second modern Seasonic power supply in one of my computers. The Seasonic M12 II 520 watt power supply was the first of their modern models and impressed me enough to try more Seasonic power supplies. These models are very different from the old economy models found in some old computers.
Seasonic X series
The Seasonic X series 560 watt power supply is the quietest current model power I can find for medium size computers, desktop computers. and small servers. I am impressed by the Seasonic features, including the plug in cabling. The M12 II is no longer in the local shops. The Seasonic X series is the replacement for the M12 II, has all the good features of the M12 II, and is more efficient.
The packaging is a bit over the top and i would happily accept a few dollars off the price instead of the fancy pack.
In My next PC, I describe a spare computer I built that was faster than my current desktop computer so I swapped the two. I needed up to 450 watts. The X series 560 watt is the smallest X series equivalent.
Assume you currently need a standard power supply of 700 watts. If you move up to an 80 Plus Bronze rated power supply, you might need only 600 watts. If you move up to an 80 Plus Gold rated power supply, you might need only 550 watts. There are calculators that can estimate your power requirement and most will adjust for the bronze level but may not adjust for the extra efficiency of the gold level.
I usually calculate the power for the maximum number of disks I can fit in the case. There was no X series gold power supply of the right size so I purchased the nearest larger size, the 560 watt. In theory I can add an add-on card in every motherboard slot and add several more disks than the case can handle. In practice, by the time I upgrade, the new items will be more efficient and might reduce the power usage.
80 Plus Gold
The previous power supply was rated as 80 Plus bronze. An 80 Plus Gold rated power runs at about the same efficiency when supplying an average load. The Gold version has a significant efficiency advantage at very low loads. When you system is waiting at idle, while you are reading email, the Gold rated power supplies can drop down to a lower level of power usage. The small extra cost of the power supply, compared to a Bronze version, would be repaid by savings in electricity over several years if you leave your computer on all day, every day, and rarely run it at peak usage.
Backup servers, test servers, and those spare experimental desktop computers all jump to mind when I think if lower power idle usage. In Web development, you might edit code for nine minutes and 43 seconds then test on the server for 17 seconds. you are saving power during the 9 minutes and 43 seconds of idle operation.
Every time I replace a magnetic disk with an SSD, the power usage goes down. 80 Plus bronze rated power supplies continue to burn a similar amount of energy at lower power because they become less efficient. Replacing a magnetic disk with an SSD might not produce a power saving with a Bronze rated power supply. 80 Plus Gold rated power supplies maintain their efficiency down to lower levels. Replacing a magnetic disk with an SSD produces a real power saving when using a Gold rated power supply.
The X series is quieter to start with. The 80 Plus Gold rating means the power supply burns less electricity when idling and produces less heat when idling. Your fans can run at reduced speed. Your computer is quieter.
The X Series 560 watt is so efficient at low power that the power supply fan switches off for long periods.
The Seasonic X Series is quieter than most other power supplies. The 80 Plus Gold efficiency makes the whole computer extra quiet when idling while I read or type.