Even if the processor draws 250w, the cooling should be completely sufficient. The cooling elements are very large and there is also a backplate. Even at 30+ minutes of full load, the cooling is probably good enough. Especially if there is still an airflow in the case. If, for example, an i9 12900k is running at full load (PL2 with 250W+), then the fans must rotate at least 80% even with a 240 or 360mm AiO, which is usually around 1000-1200rpm with "normal" fans. Even if you have a good AiO, the processor would probably overheat first, rather than the VRMs (voltage converters) on the mainboard. I know someone with a Crosshair VIII Formula and a R9 3950x, which also sometimes draws 250-300w (OC). Absolutely no problem. Can't guarantee anything, but I'd say it fits without any problems. I will also consider buying this motherboard. I haven't read anything on the Asus website or in the manual that a water cooling system is required... So I would say 95%: Safe to buy. Even with an overclocked i9 12900k.