FSP500 – Platinum 500W short FlexATX PSU

Follow this project on your favourite forum!

smallformfactor.net (SFN/SFFn): HERE
overclock.net (OCN, deleted): HERE
[H]ardforum: HERE


The FSP500-50FSPT is a short FlexATX PSU rated at 500W power output and 80+ Platinum efficiency, made by FSP.
As is typical with these PSUs, it is not available in retail stores and doesn’t have any connectors for graphics cards. I want to change that, so we need to plan out a custom version of this PSU with FSP or one of their distributors, and then either convince a major retailer to stock that unit or make it available via crowdfunding.


  • Dimensions: 150×81.5×40.5mm
  • Volume: 0.495L
  • Power Rating: 500W
  • Power Density: 1010.1 Watt per Liter
  • Efficiency: rated 80+ Platinum, no further details available yet
  • Rails: +3.3V: 15A, +5V: 18A, +12V: 2x24A
Detailed specs of the stock unit:
The unit has a PMBus connection, which can be interesting for very specific projects and server use.
It is missing the -12V rail, which is a problem I’m working on solving. Some motherboards check whether -12V is present and refuse to POST without it.


 To convince both FSP and a retailer that this PSU has potential in the consumer market, we need to compile a list of people that are interested in buying one or more units of it.
For a stock or slightly customised version, the MOQ (minimal order quantity) is 300. This includes a different colour for the case or different connectors and cable lengths.
For more complicated customisations that require some design work (modularity, adding a -12V rail), the MOQ could be much higher.
To express your interest in this unit, please answer this poll: