My friend and I did the same build except he has a full size gaming case and I have a mid-size case. I figured my cpu fan was speeding up due to heat and constricted space, but now wondering if maybe I didn't quite seat the cpu cooler and is the fan overcompensating for that. Is that feasible or is this likely just case too small? His fan is barely audible, mine is so loud I am contemplating moving the PC through the wall to the other room.
Before you compare an apple to an apple and before you can confidently say that they are identical, you need to establish grounds for the to be identical.
Mind sharing the specs to your build, like so:
Are they both identical(except for the case)? If so, then please mention the case you're working with, as the only outlier. Then we'll need to know what both your ambient temps are and if you both of you have the same taxation in terms of tasks on the system.
Motherboard: ASUS PRIME Z370-P LGA1151
Ram: Corsair Vengeance LPX 16GB (2x8GB) DDR4 DRAM 3000MHz C15
SSD/HDD: Samsung 860 EVO 500GB 2.ginch SATA III
GPU: EVGA GeForce GTX 1080 gaming acx 3.0, 8gb gddr5x
PSU: EVGA Supernova 750 G3
Chassis: Cooler Master Gladiator 600
OS: Windows 10
He is in his first floor with dogs and when he did our rebuild his case was dust covered. Mine is in the basement closed room so much cleaner. Both playing the same game, same programs active. I should be in much better shape other than the smaller case (GPU was very very tight fit). I did install two additional side fans to see if that helped keep the CPU fan lower, but it did not. The CPU fan is part of Corsair H60 120MM Liquid CPU Cooler. I am wondering if this is simply a case issue, or should I try reseating the fan (wasn't sure if it's binary, I either seated it or not, or is there a linear progression, you could be close and it overspeeding to compensate?)