Now attach the internal wiring. Start by attaching all of the front-panel wires to the adapter that Asus thoughtfully provides; then plug the adapter into the motherboard itself. This process is much easier than trying to install each individual switch connector to the motherboard.
Remember to install the USB front-panel connectors, too. New motherboards and modern cases often have two different types of connections: one for USB 3.0 front-panel ports and another for USB 2.0 ports. The USB 3.0 type is bulkier and the cabling is often stiff, so routing and aligning the connector is something of a chore. Also, if you plan to use headphones, don't forget to install the audio front-panel connector.
After the motherboard is in place, you'll need to prep for the power supply installation. This is where the modular connectors used in the Seasonic PSU are a godsend, because you attach both the main, 24-pin power connector and the eight-pin ATX12V CPU power connector to the motherboard. Again, you should do this before you install the PSU. You may also want to attach the power and SATA data cables to the SSD and optical drive at this point.
Attach the side-case fan power connector to the second fan connector on the motherboard. This is adjacent to the CPU fan connector. Unfortunately, the Asus board lacks a third fan connector, so the front-panel fan will have to be powered by a dedicated four-pin connection from the power supply itself.
Installing the power supply and graphics card
Now, before you slide the power supply into the case, attach all of the power supply connectors that you've attached to the internals of the system to the PSU. The whole affair is a bit messy looking, but it will make life much easier very soon. Since you haven't installed the graphics card yet, you may want to attach the PCIe graphics power connectors to the power supply as well. The last connector you'll need is the old-style Molex four-pin power connector that you'll be using for the case fan.
The Coolermaster case includes a power-supply extension that protrudes out the back. Detach it (by removing four screws), attach it to the power supply, and then slide the entire assembly back into the case.
Slide the power supply into the case slowly, routing the bulky main cable as you push in the PSU body. The Elite 120 case has plenty of internal room for routing the long power cables so they're out of the way. Make sure that nothing blocks the CPU fan, as you want it to spin freely. Once the PSU is in place, dress any remaining wires and cables before installing the graphics card. That will make everything look neater, as well as keeping stray wires out of the fans and improving airflow.
Remove the two back-case brackets in preparation for installing the graphics card. The graphics card is long, and you'll need to align and wiggle it a bit. The trick is to get the top of the card bracket under the overhang on the open slots while angling the card just a bit toward the case side so that you can align the connector to the PCI Express slot. Work carefully, as the front-panel audio motherboard connector barely fits underneath a cutout on the graphics card connector.
Your final steps are to fire up the system and test that everything's installed properly. I do all of my initial testing prior to attaching the top shell on the case, so I can quickly move wires around that may be blocking fans. Once the initial testing is complete, I install Windows 8 onto the SSD. The most tedious part of the entire process involves installing all of the drivers and Windows updates. Only then do I attach the case shell to the case, completing the main build.
Once I had completed the Windows setup stuff, I carried the box out to my living room. The system attaches to my Onkyo receiver via a single HDMI cable, which handles both graphics and audio.
I had to fiddle with Steam a bit to make it automatically log on to my account and start in Big Picture mode. So far, I've played Borderlands 2 and Torchlight 2 using the Xbox 360 PC controller, and it's all been smooth as silk. I'm not great with a console-style controller, but everything seems to work pretty well. My only real complaint is that I wish the Xbox controller also worked with the Windows 8 Start screen, but you'll need a mouse, keyboard, or touchpad for Windows navigation.
After running the system for a few hours, I'll probably replace the front fan on the case with a slower, quieter fan such as the 800-rpm or 1200-rpm Scythe S-flex fans. The Coolermaster fan's noise is just barely noticeable, but you can hear it when the system is idling. In-game, however, the booming multichannel audio drowns out any PC noise. The system idles at 49 watts, but I'm sure I can lower the idle power by a few watts with a little tweaking.
At $1675, this is a fairly pricey little PC, but it looks good and it offers an uncompromising HDTV gaming experience. I'm sure it will compare favorably with the fabled Steam boxes (which may start hitting the market this year) from Xi3 and other hardware vendors--and my machine will continue to perform well in future games--at least, until I upgrade to a 4K HDTV.