I honestly don't care about a psu being platinum (useless imo, if you factor the HUGE price increase). Actually, the only thing that matters is that the voltages are stable as a rock... and that the psu be as silent as possible.
Asking for a 450W passive sfw psu... won't happen. Just look the size of the heatsinks used on atx versions....
High efficency means reduced need for cooling, so Platinum is always something to strive for. Considering the small heatsinks needed in the passive Seasonic X-460FL 460W ATX psu, I honestly don't believe it impossible to have a passively cooled 450W SFX psu.
Yes, an SFX psu has quite a bit less volume than an ATX, but going Platinum should fix the problem. Not saying it would be easy, or cheap, but possible.
Here's a shot of the sinks in the X-460FL, and note that it is "only" Gold certified, so they could possibly be even smaller:
That said, I 'd prefer higher power output instead of fully passive cooling, as long as the fan is quiet.
Last edited: