We would like to thank FSP for supplying the review sample.
Server PSUs consist of at least two or more power modules in order to offer the highly desired redundancy which makes sure a power module's failure won't affect the system's up-time. In desktop PCs, a possible PSU failure and the down-time it will cause aren't mission critical, as opposed to servers, which is why no one has thus far bothered to offer a redundant PSU for this market segment. This is about to change with FSP's Twins line, which currently only consists of a PSU, though FSP has said that another with a higher capacity will be added soon.
There are probably some users with deep pockets who don't mind investing a significant amount of money into a PSU with redundancy a normal ATX chassis can accommodate. Those are the users FSP had in mind when it came up with the Twins line idea. Although 500 W may look like very little, it is enough for a low TDP CPU and a new graphics cards, given both feature low power consumption. Such a PSU isn't there to power a strong gaming station, but a PC that needs to be accessible around the clock with as little downtime as possible.