[weblacky]

Both throttle, but they don't have the same curve profile. Basically it's been shown that the Sony's delay in even starting the fan let alone ramping it up to the speed you need. The Sony's are basically quieter because they don't run their fans hard at all until it's really trying to play catch-up and it's almost too late. So both power supplies have variable speed fans but they don't operate at the same curves. The Nidec runs its fan starting at lower temperatures, in fact I don't know that I've even seen one of these PSUs not running its fan.

Basically if it were a race the Nidec launches off the start line immediately and starts speeding up, the Sony doesn't. What we need is somebody who's willing to study the circuit that controls the fan on the Sony variant and find a way to shift the curve to the left, that is we needed to start sooner at a lower temperature. If we could do that the Sony would actually be a superior power supply based on how smooth the power is at a slightly better power factor correction. But not by much.  It's not a night and day thing.

People have suggested hardwiring the fans with a potentiometer but nobody actually wants this unless you just want to run your fan 100% all the time and you don't care. I haven't gotten into this and won't for quite a while. So if somebody wants to beat me to it they're welcome to do it. Eventually I think I'll get around to it but that's after all the major workstations have rebuilt power supplies available.

I understood this for the Sony PSUs, but is that true for the NIDECs too?