The Fractal Design Define R5 Black has a the ATX form factor. ATX is the most ubiquitous of case standards, providing the largest array of compatible hardware on the market. Using the ATX standard, the case can house motherboards and power supplies with form factors ATX, Micro-ATX and Mini-ITX. The dimensions of the case itself (LxWxH) are 531mm x 232mm x 451mm.

The Fractal Design Define R5 Black has seven expansion slots, so there is plenty of room for extra components, which may be a deciding factor when planning on the longevity and build type of a PC system. The case has two 5.25" drive bays, which There are no 5.25" drive bays, but there are eight 3.5" drive bays, which is more than enough space as long as you do not intend on installing an optical drive. Installation of hard drives into these drive bays is made all the more easier by screwless rails that allow tool-less mounting.

Made primarily of Plastic, the Fractal Design Define R5 Black is built to be lightweight, but strong enough to keep your components protected. Plastic cases generally have a thin metal layer to improve protection, and are also generally fairily cheap. Whatever your case's material, it is important to keep a consistent airflow so that heat doesn't build up inside. It is therefore advised that you make use of the available built-in case fans and fan installation sections.