A Closer Look – At the Inside
Removing the top and both side panels provides a nice view inside the Cosmos S enclosure. As we mentioned earlier, the chassis is now made out of aluminum instead of steel, which makes the case noticeably lighter.

Looking up into the motherboard area you can see the three fan locations at the top of the case along with the two 120mm exhaust fans (top and back). Instead of labeling the motherboard stand off locations on the motherboard backing plate, Cooler Master included a paper template that shows which holes are used for ATX and E-ATX formats. There are a total of 7 expansion slots and each slot cover is held in place with a dedicated machine screw (no tool-less quick releases here).

There are two vent openings on the bottom of the case and they both come with removable dust filters. The large black opening at the rear is for mounting the system power supply. The filter bracket serves as a support shelf that can easily accommodate some of the larger, high-capacity power supplies. This is designed to allow a power supply with a bottom mounted intake fan to draw cool room air in directly thru the bottom of the case. The dust filter for the optional 120mm fan located towards the front of the case is accessed from underneath.

Turning our attention to the front of the enclosure you will see a column of ten 5.25” drive bays. The lower three positions are occupied by the new 4-in-3 HDD cage. Eight of the positions are fitted with a tool-less push-pin drive retention mechanism. Alternately pushing the large blue button in the center either engages or releases two pins, which lock a drive into position. The top 5.25” bay includes an insert for installing a single 3.5” device.
Cooler Master has re-designed the internal 3.5” drive bays for the Cosmos S. Instead of having six individual trays, the Cosmos S uses a single 4-in-3 HDD cage. Four HDDs can be mounted into three 5.25” bays. The HDD cage is removable and can be repositioned if you like. It comes with a 120mm cooling fan attached to the front side, which incorporates red LEDs.

The HDD cage assembly is held in place with four machine screws (two on each side). The cage attaches to the main chassis via two mounting plates and rubber grommets for vibration isolation. Individual HDDs are mounted with standard machine screws; more about this later.

Here is a view from the right side with all the exterior panels removed.

All of the miscellaneous cables come pre-attached, are neatly labeled, and appear to be of adequate length. The 24-pin ATX adapter cable is used to supply power to the touch-sensitive front panel.