corsair h100i vs noctua nh-u12p se

[Asbaat]

^ says it all

 

[dwatterworth]

The noctua cannot dissipate nearly the same amount of heat at all. Depending on your case and how you configure the h100i and the noctua, the Noctua may dump more heat back into the case. H100i does double duty of exhaust or intake, so you will need to buy fewer fans.
The noctua at low speeds will be much more quiet than the h100i. At medium load the H100i will probably be more quiet, again, depending on your case and computer configuration.
The H100i, if the radiator mounting locations are available, can sometimes fit in more cases due to the height of the noctua cooler.

The two are really completely different and hard to compare. Can you provide more specific use cases and your computer configuration?