The Plan was to have a gaming machine thats very quiet in idle. I'm pretty happy with the result so far. I have Win7, Mint Linux and Mac Os X (Hackintosh) running on the machine.
The WD Caviar Black would probably not be your preferred hdd for a silent build I just happened to have one from my old PC. (as of now I would just buy a caviar green) The Caviar Black makes pretty loud noises when it's reading small files but that can be reduced to a minimum when using AAM (Automatic acoustic Management) although it does increase access times a bit.
If I now turn the Case fans to 5V and the hdd goes into standby I can basically hear nothing at all 1m away from the case. - Mission Accomplished.
the gigabyte 7870 has such a strong cooler that you can run it with a constant fanspeed all the time. At 27% fan speed I can't hear it from outside the case and still get 70 degree celsius under load.
7870 overclocking: currently running 1,25V 1150Mhz Clock 1450Mhz Mem (Mem can be pushed pretty far, thats just the default afterburner cap). Crashes from 1175ish at this voltage, but I don't need more power for anything atm. Turned CCC off because it somehow messed with my card and gave me way too low benchmark scores and fps. (Not tested if that also applies in games)
Unigine Valley Extreme HD preset: Score - 1504, FPS - 35.9, minFPS - 17.2, maxFPS 68.9 without any Tweaking
3DMark 11 Performance Preset: P8245
the stock fans on the fractal design case are not bad. They only have minor bearing noise which really helps because I don't have to spend another 30€ on fans ^
also a huge + of the case is the use of dust filters on all intake fans including psu aswell as easy access to the front fans as visible in one of the pics
the be quiet 580w (manufactured by FSP) is really silent, looks good and has Cable Management (ATX cable not modular)
Problems / Difficulties
the fan on the scythe mugen (scythe slipstream pwm) has a distinguishable bearing noise at all speeds (only matters when its really quiet) but as I tried to make the build completely silent in idle I had to replace it. Probably could've rma'd it but I didn't notice the source of the noise at first.
the default fan curve of the 7870 starts at 40% and goes up to 50% under load. With those fan speeds you can hear some wind noise from the closed case but it cools your gpu to ambient temperatures. But as I didn't want to hear anything in idle I adjusted the fan curve with afterburner. Also I did not find a tool that supports flashing the bios of a 7000 series chip to change the default fan curve. Because of that it will still use the default fan curve under linux / hackintosh :(.
the graphics card produces loud coil noise if running at very high fps values. Not much of a problem as it doesn't happen under 300fps and is easily fixed with vsync / frame cap.
- swap scythe slipstream cpu fan with be quiet shadow wings pwm
- adjust cpu fan target in efi
- undervolted 3570k by -0,1v to get lower temps
- set custom fan curve of 7870 in msi afterburner
- set AAM Value of WD Caviar Black to 128 using hdparm under windows