The design of the Obsidian 650D is very much in line with the other cases in the series, the 700D and 800D, with a number of small differences to accommodate the mid-tower form factor. Instead of the five drive bays that we find in the larger cases the Obsidian 650D offers four. In addition the bottom part of the front of the case has a quick release dust filter that hides a large 200mm fan.
The Obsidian 650D is manufactured in a steel structure with black brushed aluminium faceplate and measures 21.5" (L) x 9" (W) x 20.5" (H) or 546mm (L) x 229mm (W) x 521mm (H).
At the top of four optical drive bays on the front of the Obsidian 650D we find a soft touch power button and a drive activity light. Both of these are illuminated in white, which offers a nice contrast to the black finish on the case. Next to the power button is a press to open cover which hides the front panel connectors.
The Obsidian 650D offers two USB 3.0 ports, two USB 2.0 ports, a Firewire (IEEE 1394) port and headphone/microphone 3.5mm sockets. Above the front panel on the top of the case Corsair has included a hot swap drive bay for connecting an SSD drive. This bay can be covered by a sliding lid when not in use and also included is a three step fan control switch.
The top of the case also features a large grill which covers a large 200mm fan. This top fan can be replaced by dual 120mm or 140mm fans and is the ideal location for a dual radiator if we wanted to install a water-cooling system.
Turning round to the back of the case we find a 120mm exhaust fan located next to the I/O shield location. Beneath the fan there are two water-cooling tube holes with rubber grommets which sit beside eight expansion slots with perforated covers. The PSU location is at the bottom of the system and at the top there is a hole for the external USB 3.0 cable wiring.
The left side of the Obsidian 650D has a quick release side panel with a large perspex window that allows us to view the majority of the internal components. The right side of the Obsidian 650D is a single black panel however it also has the tool free quick release design.
At the base of the case there is an easily accessible dust filter covering the PSU intake fan. (All of the dust filters provided with the Obsidian 650D are very easy to remove for quick cleaning). The whole case is supported on two large feet at the front and back which run across width of the case and feature four rubber, non-slip sections. These feet raise the case approximately 2cm off the floor/desk which allows for excellent circulation of air in and around the PSU.