Silverstone just released a new model in its Nightjar family of passively-cooled power supplies. Like its brethren in the series, the Nightjar NJ450 is fully modular and bears an 80 Plus Platinum certification. There are no gimmicks here; this unit isn't "partially passive" or anything of the sort. The NJ450 doesn't have a fan, and the external casing is a series of ribbed plates that serve as heatsinks.
Unlike the last Nightjar power supply we looked at, this model specifically fits the SFX-L form factor. For those unfamiliar, SFX-L power supplies have the same height and width as regular SFX units, but they're deeper. Silverstone created the SFX-L category, and at the time the company said that the object was to allow SFX power supplies to use 120-mm fans. That's clearly not the case here, though.
The fully-modular NJ450 comes with the usual 24-pin ATX power connector, a 4+4-pin EPS12V cable, eight SATA power connectors, and a whopping four 6+2-pin PCIe power cables. Given that the PSU's maximum capacity is 450 W, we would be leery about using all four of those connectors at once, as doing so would enable the connected cards to draw 600 W from those plugs alone. In any case, the NJ450 should be more than capable of powering all but the most insane machines—especially considering that it will fit in many SFF cases.
Silverstone hasn't mentioned how much the new Nightjar will cost when it hits the market, but expect to pay a pretty penny for the privilege of Platinum efficiency in a package this quiet and petite. As a point of reference, its ATX brother the NJ520 currently goes for $149.