I would prefer the H80i. Sure the H90 has a 140mm Thin Rad , but it can't be as good as the 120mm Thick Radiator in the H80i. The radiator ( rad ) is what cools the coolant , and therefore one with more overall area is better ( For e.g a Thick 120mm Radiator can easily beat a thin 140mm Rad , as it's area is more than a thin 140mm one. ) Also the tubing and cold plate isn't good at all. The tubing affects the performance of the flow of coolant from the reservoir ( the place where the coolant is stored ) to the Water block ( the block/devie which cools the part to be cooled ) Plus most case don't have a 140mm mount. On the otherhand the H80i has a much better tubing , better pump , 120mm mount which most cases have , and most importantly Corsair Link support inbuilt , eliminating the use of the other Corsair Link devices to function. The Corsair Link software will help you to adjust the pump speed , know the temps , etc. So my vote goes to the H80i. Also look for other coolers , like the NZXT Kraken X60 if you can get it as its amongst the best CPU Closed LC cooler