Reading PCPer's review of a redundant PSU, a line jumped out at me:
While FSP don't publish the dimensions of the FSP520-20RGGBB1 modules directly, their face dimensions are at a maximum 1/2 of the face dimension of the carrier, or a maximum of 75mm x 75mm x 190mm, or 1.07L. Probably a little less than this (I'd guess closer to 60x60x180, or 0.65L).
The drawback is that tiny little screamer fan, though it is mounted externally so easily removed and could be replaced with a larger ducted fan or shared airflow fro ma case fan, and the need to 'fool' the module into turning on outside of its intended housing. The card-edge connector could be used as a pair of big solder pads, or a card-edge socket used to make it easier to remove/install the PSU (said connector could even be integrated into a DC-DC solution.
It's also not the cheapest option: the FSP Twins is $400 on its own, making the module cost somewhere around or just below $200 (two modules plus the carrier).
Each of those FSP520-20RGGBB1 modules is a 520W 92% efficienct single-rail 12V supply, feeding via a card-edge connector (AKA nice big solder pads that sadly lack strain-relief).The modular power supplies only produce +12V and +5VSB, so the +3.3V, +5V, and -12V outputs are all generated on the main PCB inside the enclosure. Current limiters are used to turn the single +12V output from the modular power supplies into three 16A +12V outputs.
While FSP don't publish the dimensions of the FSP520-20RGGBB1 modules directly, their face dimensions are at a maximum 1/2 of the face dimension of the carrier, or a maximum of 75mm x 75mm x 190mm, or 1.07L. Probably a little less than this (I'd guess closer to 60x60x180, or 0.65L).
The drawback is that tiny little screamer fan, though it is mounted externally so easily removed and could be replaced with a larger ducted fan or shared airflow fro ma case fan, and the need to 'fool' the module into turning on outside of its intended housing. The card-edge connector could be used as a pair of big solder pads, or a card-edge socket used to make it easier to remove/install the PSU (said connector could even be integrated into a DC-DC solution.
It's also not the cheapest option: the FSP Twins is $400 on its own, making the module cost somewhere around or just below $200 (two modules plus the carrier).