I would set both rads to intaking cool ambient air.
By having both rads intaking the coolant temp is as low as it can be, so the air going into the case is cooler. With one intake one exhaust the coolant temps are higher so the air going into the case is warmer and the overall air flow rate is lower too.
In testing most cases will work better with both rads intaking but I haven't seen the o11 specifically tested.
Its commonly suggested that rads intaking will cook the internal components but when you have two rads worth of airflow going through the chamber it provides more air to cool and its lower temp air too so heat can't really build up.
Last edited by Ashcroft; 12-21-2018 at 04:33 AM.