If you ran a newer CPU at the effective performance of a 9600k you could probably get away with a passive cooler. A last-gen i5 mobile processor outperforms at

If you ran a newer CPU at the effective performance of a 9600k you could probably get away with a passive cooler. A last-gen i5 mobile processor outperforms at 9600k with a 45W TDP. People make a ton of noise about the efficiency of processors that are explicitly designed to be the hotrods of desktop computing: meanwhile we've also seen the bottom end get significantly faster over the years. Conversely, the floor for TDPs have barely risen.