My power supply also makes no noise I can hear. System is totally silent but when I get the GPU , and the ones I:m looking at do not spin the fans until 60C, will probably produce some noise when gaming.
My case has sound proofing and is one of the reasons I went with the Fractal Design R5.
Fanless power supplies are a good thing but I didn't look into them.
I have a similar setup and I also got a GPU that shuts off the fan at low load. When gaming it's the loudest component by far, but out of respect for my neighbors I always use headphones for gaming anyway, so I still don't hear the fans.
Like sublunar I was a bit paranoid about the PSU fan, so I got one of these that are passively cooled up to a certain threshold and then spins up the fan:
http://www.newegg.com/Product/Produ...m_re=evga_platinum_750-_-17-438-057-_-Product
In practice it doesn't matter since the fan in that PSU is as quiet as the case fans that came with the R5 case. But still, fans can get louder with wear, so maybe some day I will appreciate the fact that it shuts off at low load. The PSU and case are probably the parts I will still be using when everything else has been swapped out, so I could justify overspending a bit on them.
I got a semi-passive CPU cooler that fools the motherboard into thinking it is spinning even at low load when the fan is shut off. That way you can get passive CPU cooling at idle even on the dumbest motherboards. But with a competent motherboard the same can be achieved with any CPU fan.
In total this means that the only things spinning at idle are the whisper-quiet case fans in the R5. And I can only hear them if I stick my ear to the vents. So I got myself a 10m HDMI cable and now my gaming computer is doubling as that HTPC I wanted when I started hanging out in this thread.
It's really fun building a PC after having considered a Mac mini with 16GB RAM and 512GB SSD. The same money goes a loooong way when building something else. I was even able to get the Intel 750 SSD. I got the 400GB one so smaller than the one I considered for the mini, but much faster.