While this is true they are not completely soundless – there’s always noise caused by electrical parts which is very difficult to suppress and can actually be even louder than a rotating fan. By and large they are built like regular active PSUs but with the major difference that their fan is usually dormant and only springs into action when the system crosses a pre-defined performance limit, usually something between 40% and 50%, or a certain temperature threshold.īoth of these technologies claim to be extremely silent as no mechanical noises occur when the fan doesn’t rotate. This brings “semi-passive power supplies” into view.

This means that from this point on you simply need something actively dissipating the heat thus preventing overheating and shutdown. Sounds super, but has one major drawback: This only works up to a certain performance limit as crossing that threshold bears the very real risk of overheating the system. “passive” means that the PSU comes completely without a fan, the heat dissipation is completely being taken care of by a big heat sink – which means that the system is pretty much noiseless.

But there are two developments in that field that cropped up in the last few years and warrant a closer look: passive and semi-passive power supply units. Our approach to PSUs is to equip them with high-grade components and put a very silent fan on top. There’s absolutely no reason for having to endure a loud power supply unit anymore, as was quite the standard about 15 years ago.

Diy psu shroud