Summary: The X40/X41 and H90 all use the same basic parts made by Asetek but differ in many ways. I got this over the X40 because it had a better warranty period and was much cheaper than both the X40 and X41 at the time. The X40 only had a 2 year warranty vs the 5 year warranty of the H90. NZXT then released the X41 and gave it a 6 year warranty, 1 year longer than Corsair plus it has more features and performs better because it has better fans.
Summary: I have full atx cases and a large htpc case, the H90 doesnt fit any of them due to the radiator being too thick or tubes too short. I potentially could have gotten this to work in just about any case if the tubes werent so short. I spent 6 hours total on the web last night looking for a htpc case that this would fit into and sadly there's no definitive solution except doing trial and error.
Summary: This cooler is on par with the H80i in temps. Pro: Price, size. Cons: Only 1,500 RPM on pump vs 2,300 RPM for H80i. I have to RMA my H80i and this H90 is a temp cooler while I wait. On the box it says 55c at 100% load on a 3770k at 4.6 GHz. Which is a total lie. My 3770k with 1.128 volts at 4.3 GHz hits the low 70's. That is with push/pull, using my extra screws from my H80i. Plus the fact that my ambient temp is 22c...
Corsair Hydro Series H90 is the best single cooling fan Liquid Cooling System for an over clocked Intel 4790K processor.
28 July 2014
Summary: The Corsair Hydro Series H90 is designed in Denmark and manufactured in China. This is the best single cooling fan Liquid Cooling System for an over clocked Intel 4790K processor in the computer market. It has efficient 90+ cubic feet per meter airflow. It has appropriate nine centripetal vanes and the obligatory fluid bearing hub for longevity of the fan assembly. The minor wind noise is very acceptable. Have done the research, testing, and assembly.
Performance is great. The pump is dead quiet but the fan ...
Petr Valcik, Amazon
24 July 2014
Summary: Performance is great. The pump is dead quiet but the fan that comes with it is junk. On the 3rd day is started rattling. At first only when it would be on 60% power or less. So I upped the lower threshold and it helped...for 2 days. Eventually I ran the fan at full speed so that it wouldn't rattle too much as it moves up and down on its shaft. Then I replaced the fan with a 140mm Noctua which uses less power but seems to work better.