Peeling away the panels
With Cooler Master's clever latches at the rear, it's easy to pop off the Cosmos' left and right side panels to get at the case's internals. Before diving inside, though, it's worth spending a moment on the side panels themselves.

A testament to Cooler Master's desire to lower noise levels, the panels feature a layer of foam to absorb noise generated inside the system. The foam also adds a measure of insulation, but given the Cosmos' array of cooling fans and vents, that shouldn't be a problem.

There isn't much action over on the right-hand side of the case, but a few features demand our attention. Note that all the cables for the top panel's expansion ports and connectors snake down this side of the case, nicely out of the way. A couple of long vertical holes—whose sharp edges are neatly draped in protective plastic—provide access to the other side of the case. In addition to front-panel connectors, hard drive cabling also needs to be run through these holes to get at the motherboard.

Note that there are also a couple of holes cut into the top and bottom of the motherboard tray. Ideally, these would allow you to stealthily run power cables from the PSU at the bottom of the case to motherboard power connectors located at the top. Unfortunately, this doesn't work out so well in practice. See that horizontal strut running across the inside of the case near the top? It contains the latching mechanism that holds the side panel in place, requiring a tight fit that doesn't play well with cables running across it.

Around the other side of the system, we get a better look at the Cosmos' internals, including the plastic ducting that runs across the middle of the case. Cooler Master calls this the case's "wind tunnel," and it's meant to provide increased airflow for graphics cards. However, it doesn't actually contain any active cooling elements. Wind, in this case, is caused by the negative pressure generated by the case's fan layout.

"Negative pressure" sounds like marketing-speak, but it's a simple concept. The Cosmos comes with four 120mm fans, only one of which actually sucks air into the system. The rest serve as exhaust outlets, and for the airflow to balance out, air is drawn into the case through a number of vents. One of those vents just happens to sit alongside the wind tunnel.

Another sits in the case's bottom panel just below the power supply, with additional venting found below the hard drives bays. The case's bottom panel also contains its sole intake fan, which is covered by a plastic grill to protect it from stray cables.

The bottom-mounted intake faces a pair of exhaust fans located at the top of the system. With the power supply tucked out of the way at the bottom of the case, these exhaust ports should have no problem exhausting hot air from around the CPU socket. If the stock 120mm units that come with the Cosmos don't move enough air for your needs, the case is also drilled to accept larger 140mm units along its top panel.

Out of the box, the Cosmos uses the same 120mm fans throughout. They're quiet models, spinning at just 1200 RPM when plugged into a standard four-pin molex connector. The molex plugs ensure compatibility with standard ATX power supplies, and the fans will even benefit from speed control on PSUs that offer fan-specific molex headers. However, those who prefer to govern system fan speeds via three-pin motherboard connectors will need adapters for the Cosmos.

The Cosmos' final exhaust fan is predictably found at the rear of the case, sitting just next to the I/O shield above an array of expansion slots. There are seven slots in total, with brackets conveniently held in place by thumbscrews. Just below the thumbscrews in the picture above, you can see the venting for the case's graphics card ducting.