this is the problem with teh 240mm rads... very few cases have places you can mount them as intake.
using the h110i as top exhaust setup can actually make a big difference... depending on what else is going on in your case.
like if you have two non reference 680's over volted and clocked to the moon... the inside of your case is going to be warrmmmmm, perhaps even hot. and heat rises, so you're pumping hot air into your radiator and asking it to cool the CPU.
a friend had this situation going on... cpu ran ice cold benching, as soon as those gpu's were firing at 100%, the CPU was hitting thermal barriers. he had no mounts other than the top for his 240mm in his haf case. when we switched the rad to intake, it of course was better... but then the gpus were trying to cool with warm air instead of cool air. lol
ultimately, bigger is not always better. switched it out for a 120XL 120mm set as intake on the top rear mount. so front/both sides, were intake.. top rear was intake with rad, and then top fans exhaust.
everything was now getting cooled with fresh air.