What are the pros and cons of both?

also 280mm or 360mm radiator?

Honestly for AIO just look at your CPU TDP and match against the radiator's cooling capacity.

360mm rad will require longer/taller chassis.

I didn't know that, so for example R9 3900x?

So the R9 3900x TDP is 105W, and based on some wc configurators you'd be fine with the 280mm rad.

If i'm not wrong, Corsair H115i platinum cannot control fan speed and it was slightly more noisier than NZXT X63. NZXT X63 you can configure the fan speed for your radiator.

For AMD Ryzen 9 3900X, NZXT X63 is basically enough. Unless you planning to do max OC for your AMD Ryzen 9 3900X and heavy on video processing or 3D rendering then maybe you need 360mm radiator. If that you looking for, then go for NZXT X73.

Basically all those fans and AIO rpm can set from your motherboard.
Asus motherboard can set and Lian Li fan comes with app to adjust all those RGB lighting and fans speed.

This post has been edited by Benefon: Dec 9 2021, 10:20 AM

What you saying is right and wrong. Not all. Some of them require special controller with controller software from the manufacturer in order for you to customised the fan speed. Without the controller, you cannot use the mobo to configure it.

Yup, I agreed with you.
Unless u get high end motherboard