aman4672
Kinda Brings up a good question IMO. I see more people with water cooled cpus and air cooled GPUS wouldn't the reverse make more since for quietness? Especially if you go like an NHD15 or dark rock pro 4.
I guess it depends on if the CPU is water cooled with an AIO or a custom loop. Also, a good AIO still cools a CPU better than a NH-D15 or DRP4 and the AIO is also quieter at the same CPU temperature. In addition to that you don't run into all those clearance issues you get with a large CPU air cooler. That's one reason why I got rid of my large Noctua air cooler and went with an AIO before eventually switching to an open loop.
If you already have a custom loop, why not water cool both unless you don't have the space in the case for enough radiators.