Quick(ish) post... So a coupla years ago, I splashed for the Corsair H115i liquid cooler when I got my new rig:
CPU: i7-6700k
Mobo: Gigabyte Z170X-Gaming 7
Case: Fractal Define R5
RAM: G.SKILL Ripjaws V 16GB DDR4 3000
From the get go, I was unhappy with the cooling of the H115i, as alluded to in an earlier thread:
https://techreport.com/forums/viewtopic.php?f=4&t=118357&p=1319048#p1318814
It was like the liquid cooling loop just didn't react quickly enough to temperature changes.
I originally bought this gear with the intention of overclocking the i7. I started with 4.4 GHz, but that was too hot. Backed down to 4.2 GHz. Still much warmer than I thought my (then) high-end kit was capable of. It was hitting 80°c during a background virus scan. I scoured the interwebs for more effective cooling curve info to experiment with in Corsair Link. Nothing I tried worked, short of cranking the fans to top spin, which was VERY loud. The pump was set on the high setting in Corsair Link. I was very, very close to going the delidding route. After a few frustrating and fruitless attempts at re-applying the thermal paste, I decided to try the Noctua NH-D15. Glad I did.
Unfortunately, I didn't do any extensive testing before the swap, but here are a few numbers... all the same settings before and after the swap. The i7-6700k is at 4.2 GHz, the RAM at XMP 1 (DDR4 3000). (All temps Celsius):
Idle temp, H115i: 43°
Idle temp, NH-D15: 31°
Gaming-Overload temp, H115i: max 83°
Gaming-Overload temp, NH-D15: max 55°
Gaming-Doom16 temp, H115i: max 81°
Gaming-Doom16 temp, NH-D15: max 60°
Those gaming numbers are for the games Overload and DOOM (2016), my two latest indulgences. Not quite an extensive benchmarking suite, but indicative, nonetheless.
I oriented the Noctua for rear exhaust, and replaced all the top plates on the Fractal case upon installation of the Noctua (since the H115i rad was top-mounted). My system is much quieter and and much cooler. Probably gonna try to get back up to 4.4 GHz, see what happens.
(By the way, if you were a fan of the old Descent games, you, _really_ oughta check out Overload.)
I definitely respect Corsair and their products (my RM750i PSU is perfect), but I thought I should share.
Anybody wanna buy a gently used H115i? :^)