Building in the Colossus M
If you read my review of the BitFenix Prodigy M, many of the steps below will look familiar. Stay tuned to the end though, as I encountered a few unique differences between the chassis.
The power supply is mounted up front in the micro-ATX versions of the Colossus/Prodigy/Phenom, and sits on this removable rail. I used a bigger ATX power supply than necessary (180mm modular!) just to see if it would fit (it did), but if you are planning to use multiple high-end graphics cards you may want to consider choosing a 140mm power supply. If anything, it will give you more room to work and more space for cables.
The power supply attaches to the removable bracket and if your PSU uses thumbscrews you’ll be happy to know they’ll still fit when installed (it’ll just be a bit trickier to slide into place). I’d recommend installing the motherboard, CPU/heatsink and RAM first though, as things will get cramped pretty quickly. I used an AIO water cooler when I reviewed the Prodigy M, and the same caveats would apply to the Colossus M. Really, a Corsair H80i / SilverStone TD03 / Thermaltake / any other 120mm radiator seems like the best option if you simply must use an AIO kit, but if you only have one graphics card a 240mm radiator would fit nicely up top as well.
I wanted to try something different in the Colossus M though, and decided to use a 120mm tower-type CPU cooler. This is about the tallest you could fit and still install 3.5″ drives on the vertical drive mounts, but of course you would have more room without 3.5″ hard drives or by just removing the drive mounts entirely. You may also want to use a CPU cooler that allows for different mounting orientations to make the best use of your specific airflow setup (with a giant fan slot in such close proximity, you may want to intake/exhaust from the bottom instead of out the back).
With both of the side panels removed, routing cables is surprisingly simple for such tight confines. There’s enough room to work around larger CPU coolers, but I’d hold off on installing any graphics cards until the very last moment. If your front panel header on the motherboard is located along the bottom edge (top edge, in this case) it’ll be tricky to plug those in with a GPU in the way. On the other mATX cases from BitFenix you could swap the panels and plug those cables in at this point in the build; with the Colossus M you might find yourself waiting until later. They’re long enough to plug in now, but moving the case around might get tricky with a side panel attached by cables.
The Colossus M uses the same vertical drive bracket as the other cases. They install as shown above, and this arrangement actually makes connecting the SATA data and power cables pretty easy even after you install the drive bracket into the case.