To give an update about this setup:
Fan xpert2 works like a charm !
On normal use, the fans can be made inaudible for me:
* passive PSU on low load
* 2 hd-fans @ 500-600 rpm
* front intake, 1 cpu fan & top 140mm case fan: stopped
* other cpu fan & top 120mm case fan: +/- 700 rpm
This results in a very quiet setup (even with a total of 11 fans in total)
Even with all the fans on full speed (only used for extreme stressing after an OC), the sound level is very acceptable. Of course, you can hear a "whoosh", but it is a very soft & smooth "whoosh" sound.
My FT-02 with all the fans on max (the original 4 case fans and 2 CPU s-flex 120mm fans) is noisier imo and has a less pleasant sound characteristic (think the 180mm fans are to blame)
Do not that the setup above is WITHOUT the GPU, since I'll cover that below
Only downside is the Gigabyte gtx680 windforce (which has 3 fans).
Before I get into that, let me explain how I evaluate noise. For me (as a gamer that likes silence), there are 2 factors: how noisy will the system get when gaming (upper limit) and how noisy will it get during light use (surfing,...) (lower limit).
When regarding the upper limit, I have nothing but praise for the Gigabyte gtx680 & for the Cosmos II on that matter. Airflow in the case & cooling on the card work very well, resulting in low (GPU) fan speeds, even when gaming (Risen 2, shogun 2, Skyrim, Crysis 2,...) on 1920*1080 with max options enabled.
But when "idling", the fanspeed does not go below 40% on the Gigabyte, which makes it too audible for me. My previous GPU was a powercolor 5870 pcs+ and that card was nearly inaudible on low fan speeds (only 1 fan and it went lower than 40% fan speed)
Tools like afterburner and such also cannot lower the fanspeed below 40%, So I'm looking for a solution
Things I'm thinking of:
* try speedfan
* a custom/modified/updated BIOS for the GPU (I cannot make this myself, so I'm not really hoping on that option)
* custom card cooling. Best bet seems the
Arctic accelero xtreme III, but I'd need to be sure that fan speed would go lower than 40% and that the xtreme III has better fans than the original Gigabyte fans
* replace the stock fans with other fans (I'm not sure if this is doable). Basically it would be like creating my own arctic accelero xtreme III with fans of my own choosing.
Any advise there would be appreciated.
Finally, some closing comments on the Prolimatech red wings red vortex 140mm fans: These are great fans !
I won't discuss the looks since that's something personal, but I like the sound level and signature very much !.
The 120mm variations of these fans seem to be rather bad (when it comes to sound level), but their big brother delivers on all fronts: cooling, sound and looks (imho)