Waveshare Dedicated Cooling Fan for Compute Module 4 IO Board, PWM Speed Adjustment

The CM4 IO Board - the carrier board the Compute Module 4 plugs into - has its own set of components that can run warm under load, separately from the module's own cooling needs, and this fan is sized and mounted specifically to cool that carrier board rather than the module. PWM speed control keeps it running quietly during light use and only ramping up when the board's actual thermal load calls for it. A small, inexpensive addition for anyone building a CM4-based system in an enclosure where the carrier board's own heat generation matters alongside the module's.