Installing the CPU, Cooler, and Memory
The process of building an ITX-based system is actually quite different from how you build a standard full-size desktop system. The order in which you do things is critical, and for the most part, is in a completely different and nearly opposite order to how you'd build a large desktop. For example, you simply cannot start by installing the motherboard, and then proceed to the CPU and cooler, as you'll have no access to the cooler mounting mechanism once the motherboard is in the case. Furthermore, while you'd typically install a power supply before anything else in a large system, for this particular ITX system, doing so would make it impossible to proceed to the next step. In other words, if you decide to build the system profiled in this guide, take the order in which we assembled it seriously - it really won't work any other way!
So, we'll start with prepping the motherboard for installation. If you need help learning how to install a CPU, check out our Guide to Assembling a High-End ITX PC. For purposes of this guide, we're going to assume you know how to use the Intel locking mechanism. Once the CPU is in, it's time to install the CPU cooler. Note that if you'll be using a liquid CPU cooler like the Corsair Hydro H60, you'll need to carefully install the cooling block while placing the hoses and radiator off to the side of the motherboard - they cannot be detached.
We used an excellent new 120mm-based tower cooler from Arctic, the semi-passive Freezer i32. As you'll see in the photo here, it's about the biggest cooler you can install in this system. You could use some 140mm-based coolers, as Fractal Design has designed the Core 500 with 170mm of headrom, but RAM clearance could be a serious issue. As it was, the Arctic cooler's fan was touching the first RAM stick's heatsink, and this was despite using a low-profile Corsair Vengeance LPX kit. And honestly, this cooler performed so well, as we'll show later, that there's no reason to take a chance with a larger model.
Mounting the Motherboard
Installing a motherboard in a small case is always a bit of a challenge, and it's doubly-hard when it has anything much bigger than Intel's stock heatsink attached to it. That includes both tower-style coolers, as we used here, as well as liquid coolers. Tall coolers mean "threading the needle" between the side frame supports of the case, while a liquid cooler requires you to mount the motherboard while also holding the radiator assembly in the other hand. That's just how it is if you want a high-performance compact PC, folks!
Interestingly, we came upon an error in the manual for the Core 500 as we were assembling this system. While Fractal Design indicates that you must install the power supply before the motherboard, this is in fact completely wrong. Installing the power supply makes it impossible to insert the motherboard, as you need extra clearance to maneuver the ports into place, which having the power supply installed does not permit. We really have to wonder whether Fractal Design bench tested this case!
Another issue we came upon was somewhat motherboard-specific: the port placement. We found that the side-facing SATA ports, as well as the mid-mounted front panel header, made things a lot more complicated than they would be with a different board layout. You'll need to use 90-degree left-angle cables for the SATA drives (the motherboard included one right-angle connector, which worked in a pinch, but wasn't ideal, as shown below). You'll also want to make sure to connect your front panel cables at this point, as doing so after the power supply is installed is basically impossible.
Installing the Power Supply
All right, about that power supply... yes, indeed, jamming an ATX power supply into an ITX case has been the nail in the coffin for far too many previous ITX cases. We found that the SilverStone SG08 essentially could not use an ATX power supply, even though it's spec'd for one, while the Cooler Master Elite 130 can hold a very large ATX power supply, but it essentially starves the CPU of cool air. Well, Fractal Design has done its very best here, but that doesn't mean this is an easy fit.
First of all, you absolutely, positively must use a power supply that's 150mm long or less. Want to use a bigger power supply? Well, you can forget about installing your video card! Second of all, you should keep in mind that the power supply draws in cool air from the bottom of the case. Want to place the case on thick carpeting? You're going to have a cooked power supply in short order! Luckily, we found the perfect power supply for this build: the EVGA Supernova 650 GS. Based on a new Seasonic design, the 650 GS is powerful, efficient, fully-modular, and most importantly, 150mm long! Even so, you can see in the photo below that it is really, really jammed tight in this case. Also note that the PSU exhausts out the right side of the case. Want to install it in a cabinet with little breathing room on that side of the case? Again, good luck with that!
Note that we're just using four cables in this build: the motherboard 24-pin cable, the CPU 8-pin cable, a single SATA chain, and a PCIe power cable for the video card. That's the beauty of modular power supplies, and as you can see, it keeps things as neat as possible. That being said, this is of course an ATX power supply, so the cables are far longer than necessary for a build like this. We stashed the excess cabling between the power supply and the drive trays.
One other thing we'll discuss in more detail here is the issue we raised previously about the USB 3.0 header. Frankly, we think Gigabyte made a serious mistake placing the header in the middle of the board. Due to USB 3.0 signaling requirements, all internal USB 3.0 cables are thick, making them very hard to bend. Furthermore, the connector itself is quite large. What does this lead to? Component incompatibility, of course! While we got lucky with RAM clearance as well as case headroom, we were nearly done in when we went to connect the USB 3.0 cable, as there simply wasn't enough room under the CPU heatsink to do so easily. We had to jam it in there, which forced the heatsink to lean forward every so slightly. Our temperature data showed that this didn't have any adverse effect on thermal performance, but it sure would have been nice if we hadn't needed to deal with this.
Our advice: if you're going to use a tower-style cooler, skip the Gigabyte board and go for the Asus Z170I Pro Gaming, which we used in our High-End ITX Assembly Guide. It costs slightly more and has very similar specs, but its superior layout makes it worth every penny for a build like this.