I constructed this as a dedicated Steam box for placement within a home theater setup, so I wanted something that was compact and quiet, yet performant enough to run modern games at 1080p and 60 FPS. The Hadron Air case seemed like the best choice, due to its extremely compact size (roughly two Xbox 360s stacked) and understated finish.
Didn't go with EVGA's own motherboard for this, because it was more expensive than alternatives yet lacked onboard WiFi and Bluetooth support. The Asus Z87I-Deluxe fits this case nicely, and doesn't require you to adjust the CPU cooler to fit the graphics card.
Went with the MSI GeForce GTX 760 after reading the reports that it is the quietest card in its class. Those reports hold true. Under load, the system is indeed extremely quiet (I was able to dial back the fan profiles to "silent" after observing that the temperatures stayed quite low under stress). You have to press your ear to the PSU to hear its fan, and the loudest noise in the system currently comes from the CPU cooler fan on the EVGA mITX cooler assembly. I might replace that fan with a quieter one, as well as the two case fans at the top, in order to completely silence the system, but you can't hear the fans at all if you step back a few feet. It's far, far quieter than the PS3 and Xbox 360 I have in the same entertainment center.
Performance-wise, for Bioshock Infinite under the Ultra_DDoF settings (the highest you can go) at 1080p, it average 70 FPS. When compared directly to the PS4, I can max out almost all of the settings in ACIV at 1080p, providing a much better quality rendering than the PS4 while matching its 30 FPS framerate (ACIV's PC version has problems with the 30-60 FPS range, so I used adaptive VSync at half refresh to lock at 30). This should provide significant enough power to handle games at 1080p for the near future. Also, the fact that this chassis supports full-size and full-power graphics cards will probably give it a very long lifetime as I upgrade cards. The GPU dominates performance so heavily that I don't see the CPU, motherboard, or memory needing to be replaced for a while, and the SSD is good enough to make loading times practically nonexistent.
Assembly of this system in this case is tricky, and you'll need to be patient and do things in the right order. I screwed this up and had to take everything apart at least once, so I'll note the assembly order that worked for me:
First, mount the CPU on the motherboard, apply thermal compound, and affix the CPU cooler while outside the case. Otherwise, you won't be able to get sufficient leverage on the rotating connectors to attach the cooler. Then place the memory on the board and connect the CPU fan header.
Place the SSD on the drive mounting bracket and place that in the bay. Run the SATA and power cables to that, routing them and clipping them into place.
Move the rest of the cabling out of the way and slowly lower the motherboard into place, making sure not to pinch wires to the top case fans. I had to carefully work the motherboard into the back panel until all the rear connectors popped into place. Screw down the motherboard.
Connect the case fan header (both fans are on a splitter, so there's only one wire for this) and route the two sets of power motherboard connectors around the drive bay and onto the board. The smaller yellow connectors can actually be run under the board near the drive bay. Run the HD audio cable from the front of the case under the lower edge of the motherboard and onto the connector there (the graphics card will actually go over this).
Place the graphics card, being careful to work the power connectors around it. I could probably have cleaned up some of my cabling if I thought more about it, but what I have now works for me, where I clip the power cables around the drive bay. The HD audio connector we ran from the front of the system should slip under the left edge of the graphics card.
Connect the front USB cables (shame those are bright blue, unlike the black for everything else), the front power light and power switch wires (I had to look up the orientations of those on the motherboard a couple times), and the power to the graphics card. Close everything up and you're done.
Again, I'm really happy with how this turned out and may only do a couple of tweaks to the fans in order to fully silence the system. The Hadron Air is an excellent case for this kind of system.
As an update to the above (1/28/2014), I ran some performance tests and did a little tuning on the overall system, which squeezed out a fair bit more power than I initially had reported.
Out of the box, the system was set with the GPU in "silent" mode, which underclocked it. Additionally, the RAM was set to 1333 MHz, not 1600 Mhz like it should have been. As a result, initial benchmarks in 3D Mark were lower than they should have been:
Fire Strike 1.1 - 5271
Cloud Gate 1.1 - 19038
Ice Storm 1.2 - 133970
Also, one of my case fans had been obstructed by one of the wires, so the other fan was working overtime and airflow in the case was not what it should have been. You'll want to make sure that wires are well clear of your fans if you assemble something in this tight of a case. Once I resolved that, the fan noise dropped significantly, to the point where the system is silent when sitting in my entertainment center. If I replaced the case fans and CPU fan with known-silent models, I bet I could get this to be silent when sitting a foot away from you on a desk, too.
Fixing the RAM speeds in the BIOS and using MSI Afterburner to guarantee that the GTX 760 I was using was running at stock speeds and power, I was able to get the much better 3D Mark scores of
Fire Strike 1.1 - 5767
Cloud Gate 1.1 - 19879
Ice Storm 1.2 - 139219
That's a 9% improvement in the Fire Strike score just by getting everything working at the right speeds. I then tried to push it a little bit, and used MSI Afterburner to overclock the GPU just up to right before it became at all unstable. I was able to set Core Voltage to +12 mV, Power Limit to 110%, Core Clock to +100 MHz, and set a custom fan speed ramp that stayed quiet for longer while keeping things cool. Others have pushed this same card higher, but when I tried to do so, it started becoming unstable under significant load.
This led to my current Fire Strike 1.1 score of 6091, a 6% improvement over stock settings and a 16% improvement over what I initially reported. The overclocked GPU core clock is 1254 MHz vs. stock of 1162 MHz (the MSI card comes slightly overclocked out of the box), for an increase of 8%, so the 6% performance gain is understandable.
Idle CPU temperatures for both cases were 31 C, ramping to 63 C under load. The stock GPU temperature was 31 C idle to 72 C under load, where the improved fan ramp on the overclocked settings had the GPU idle at 31 C to a max of 67 C under load.