PC details:
Athlon II 250 Regor
GA-MA785GM-US2H microATX
Scythe Ninja 2 CPU cooler
HR-05 IFX chipset cooler on NB
Intel SSD
X650 PSU
ThermalTake ElementS case http://www.newegg.com/Product/Product.a ... 6811133077
DPDT Switch (12V/ 5V /0V tied to all system fans)
1x 230mm, 1x 140mm; 3x 120mm fans

This system is operated 100% passive since I leave all fans off and the PSU fan doesnt start up with power draws in typical range of 45-65 watts.

Looks good. How are your temps running fully passive?

The reported temps in speedfan are between 38-43C with "core" reporting typically between 30-32 C.

I ended up replacing the NB heatsink since it felt hot, the discussion from that experience is in this post:
http://www.silentpcreview.com/forums/vi ... highlight=

Nice and tidy no moving parts system. Is that a 2.5 -> 3.5 adapter I see used to mount the SSD.

Are you happy with the X-650, no whine/squeal noise? I chose an ST40NF psu because I like supporting passive component manufacturers. Often the PSU can make or break a truely silent build.

I'm not familar with the ThermalTake case, did you chose this case specifically for a passive build, if so why? At the moment I'm considering an FT02 case because of its "stack effect cooling" design. I'd remove all fans and filters. May even have to cut the vent grills for increased air flow, hope not.

I might try the Orochi, otherwise the Ninja 2 maybe, not sure. Probably need a mobo temp controlled fail safe fan. I'd also undervolt the CPU.

nice system.

at this point the hottest component is probably your southbridge, easily during idle and maybe even during load.
that was certainly the case for me (same mobo, sb get almost no air), i've replaced mine with a zalman nbf47 which brought its temps in line with the cpu and nb, both whom get considerably more airflow. it's a pita to install, but performance is great and its about half of the cost of a thermalright, it is chunky though and blocks the top horizontal sata port, pcie 16x slot and top pci slot.

You could also try a Zalman ZM-NB47J, which probably won't block any of your SATA ports.

I've used one on my G31-based system's SB with good results.

The Element S comes with SSD mounting holes above the PSU cover (which I don't see you using). I'm assuming the power supply cover is too small for the PSU of your's?

Just curious, what's the primary purpose of this PC? HTPC?

When I bought the intel 80gb from newegg, there was a nice bonus deal for both the Icydock and the ElementS case.

The icydock wasn't necessary since the intel retail SSD included the metal tray (2.5->3.5 adapter) seen in the picture. I chose to use the Icydock since it doesnt look to be well-vented (assuming SSD produces lower heat anyway) and I might install a laptop drive into the computer for additional storage later down the road.

Since the case was a combo deal, I didn't know what to expect. Once I saw that the ElementS had a huge vent on the top of the case, it started me towards a passive PC. The case feels cavernous with this microATX mb. I don't use the cases' bracket supporting the 2.5" drive since the bracket slightly (somewhat marginal, in reality) obstructs my PSU's vent. I don't plug in the bright LEDs for HDD/POWER status; otherwise I like the case.

I love the X-650 PSU, i haven't heard anything from it. I built this computer considering that I might later upgrade the graphics for video decoding or light games: the dual modes of the PSU would then add protection in case of high temperatures.

The SB is still pretty warm but I passed up on changing the heatsink because every option looks like it will obstruct a possible future PCIE card. The system has been stable, so I feel content with the OEM heatsink so far.

I use this PC as a desktop with a high resolution monitor for internet/light duty. I have a separate HTPC, but for that I went with a fan cooled high-power graphics/CPU that I crammed into a case.

Very nice. Have you though about removing some pci slot covers? The top fan too could be removed since it`s not working at the moment. The rear fans and the cpu fan could stay, since they`re mounted vertically they`re not obscuring convection airflow. They should be more than enough to cool your system anyway.