You can only adjust to your circumstances.
I have a CM scout 2 case with my H100i radiator placed on the outside of the case and the fans on the inside pulling air in due to space constraints with my Sabretooth z87 board. I also have one fan on the outside pushing air in. the case has a handle on the top that prevents me from placing another fan on the radiator.
So with that I am averaging 52c under load with Aida64 and an ambient temp of about 25c ( no AC in my place, just open windows & ceiling fans) and a idle temp of about 28c-34c depending on how long I allow the PC to idle.
As for the H100i the setting I'm using is quiet mode. even during Aida64 testing. My rig is silent. about 1000rpms..
I also Delidded my i7-4770 and used Arctic silver 5 on die and IHS... So you know... that helped too..
Case: CM scout 2
Widows 8 PRO 64bit
Motherboard: Asus Sabretooth z87
CPU: i7-4770 delidded running @ 4.5 with 1.04 VCORE
Cooling: H100i with 3 fans, 2 stock fans and one Cougar on outside, running in quiet mode setting
Case Fans: 2 Corsair AF 120s and one Cougar Vortex PWM (good choices, EXTREMELY QUIET)
Mem: 16G G-skill Trident 2400mhz
Vid: Asus Geforce GTX 760- will SLI soon
SSD: Samsung 840 pro 256Gigs boot drive
HDD: 2 2TB Barracudas in Raid 0
PSU: Power & Cooling Silencer 950W. Not modular but I worked it out. Looks good.
Astro A50 gaming headset