Before you start thinking about replacing the fans on the H100i, install the unit and make sure to DL the Corsair Link software for it and I would recommend setting the fans to "balanced" . I think you'll find the system is quiet at an idle, yet responds nicely to temp increases. I just finished the H100i on a customer's system and I must say I'm impressed. The system is a C5F MB with a FX 8150 running at 4.5Ghz @1.42v and no matter how much of a load I put the CPU under the temp never got over 42c.
Electronic Smoke Signals From my TechnoTeepee
ASUS Crosshair V Formula AM3+ 990FX, 1703 bios
AMD FX 8350 Vishera @ 5162Mhz [21x245] 1.546v 🙂
Water Cooled - Koolance EX2-1055, CPU 370 WB, Idle=22c Load=52c
32Gb G.Skill Sniper ddr3 1600 8G X 4 , 9-9-9-24 @ 1.55v
ASUS HD7970-DC2T-3GD5, Cat 13.5 beta 2, Dell U3011 @ 2560x1600
SanDisk Extreme 120Gb SSD SATA 6Gb, 250Gb SATA 6Gb, 1Tb SATA 6Gb x2
Win 7 Ultimate 64bit, Corsair Obsidian 800D, Corsair HX1000w PSU