Drive bays and extras
Peering deeper into the Cosmos reveals the case's hard drive rack. Located along the bottom of the case, the rack contains six 3.5" bays, each of which is held in place by a single thumb screw.

The individual drive cages slide out with ease thanks to little handles that neatly snap into plastic holders when not in use. These clips prevent the handles from rattling around when the hard drives spin up. Rubberized dampers also isolate the cages from drive-level vibrations to keep noise levels low.

Drive cables are all run on the other side of the case, keeping everything nice and clean around the cages. Cooler Master also offers an optional hard drive fan to provide the rack with additional cooling should the venting directly below the drives provide insufficient airflow for larger disk arrays.

Just above the hard drive rack, we find an array of internal 5.25" drive bays. Rather than requiring pesky screws, these bays hold optical drives in place with plastic tabs activated by large buttons on one side of each bay. It's a neat little retention system, and it holds drives surprisingly tightly.

So far, the Cosmos is looking pretty stacked, with loads of quiet fans, tool-free drive bays, and fancy panels. However, the case is missing one feature commonly found in high-end enclosures: a removable motherboard tray. This omission isn't a deal-breaker, particularly because the case's generous dimensions leave plenty of room for poking around. However, you may miss it if you like being able to pull the guts of your system out on a single, convenient platter.

You may not get a motherboard tray, but the Cosmos a few other extras that we'd be remiss not to point out. Many of these goodies come in a fancy little box buried within the enclosure.

The box contains a packet of screws, motherboard mounting posts, and other hardware required for system assembly. Also included are a couple of tiny screwdrivers to help you put everything together and a fistful of zip ties to clean up the cabling once you're finished. The zip ties are particularly useful, but they're not the only cable management accessories in the box.

Cooler Master also throws in a handful of larger cable binders that can be affixed to the case's internal walls. These reusable binders are much larger than the zip ties, giving users two ways to neatly route and hide cables within the Cosmos.

The last little extra we find will be the most important, at least for some users. Upside-down cases like the Cosmos aren't compatible with all motherboard and power supply combos because some PSU auxiliary power cables aren't quite long enough to reach some motherboard connectors. To alleviate this issue, Cooler Master throws in an eight-pin ATX 12V extension cable to bridge the gap. The extension cable won't help if your primary 24-pin power connector is too short, but we've yet to encounter a power supply and motherboard combo where that was the case.