Fan Advice: Noise vs CFM

[Machine-code]

I have a SFF case and I am limited to a heatsink of 125mm or less. I tried a Cooler Master GeminII 2 S but I am getting 75c in prime95 at STOCK on a i7 920. Reinstalled a couple of times with only a very thin layer of paste. It's a bit small for a 920 but I am space-limited.

I see FrozenCPU has a PWM 120mm Delta fan (AFC1212D) http://www.frozencpu.com/products/8565/fan-531/Delta_120_x_25mm_High_Speed_PWM_Fan_-_11311_CFM_AFC1212D.html?tl=g36c365s936 that does 113CFM @ 46.5db but can be ramped down in the BIOS. Unfortunately the BIOS (Rampage II Gene) only has 3 settings, Turbo Silent and Standard and cant be set according to temperature. The slowest the fan gets is 25% duty cycle @ 1720 RPM with no mention of sound at that speed.

I'm not super sensitive to sound and I don't mind fairly loud while gaming, I also don't want to hear a jet engine whirling.

Questions:
Kinda subjective but is this too loud?
Is this too much CFM for a heatsink fan?
Will the extra CFM cool or just be a waste? The case is a Lian Li 351 and I can't really add any fans without a serious mod.

Anyway, informed opinions appreciated.

Also, why are there so few threads in the air cooling section?

 

[tryin49]

I found that buying fans was very difficult as the data isn't always accurate. Sound can be measured from different distances and either being outside or inside a case, worse the exact testing methods aren't always specified. I've never tried that particular fan but I would think it would be a bit noisy.

If you can, I would try buying a fan controller since it would be a little easier than switching the settings in BIOS. That way you could have it loud for your games and quiet for everything else without having to turn off.