Thanks everyone for all the input.
So far the options are
- Tune the fan curves
- Tune the Linux CPU performance governors (e.g. using CpuFreq and CoreCtrl)
- Go with AIO (successful stories Arctic Freezer II 280 and Corsair H150i). This works likely because the fan speed being throttled by the water temperature instead of the CPU die temp.
- improve case ventilation (I current use the two “Dynamic X2 GP-12” fans came with the case)
I noticed that Noctua coolers come with a low noise fan adapter that I can try. I believe it works the same as tuning the fan curves in principle.
Corsair H150i is 360mm which simply will not fit in my case.
I watched some Arctic Freezer II 280 reviews and I quite like it. Good performance and relatively cheaper in price.
The problem, unfortunately, is my case has no room for stock Arctic Freezer II 280. The top side is blocked by the motherboard. Front side installation is the only option.
My GPU is Gigabyte 5700 XT GAMING OC 8G, which is fairly long (279.85mm in length).
Meshify C has a 315 mm GPU max length with front fan (25mm) mounted, which is 340mm without fan.
So with GPU only there is 60mm left.
Arctic Freezer II 280 radiator is 38mm + fan 27mm = 65mm. This won’t fit the 60mm clearance left.
I do have a spare CryOrig XT140 slim fan which is 13mm thin. So maybe I can switch a fan with that…