A personal cluster computer comprises a cuboid cabinet (2), an internal frame (10) and four motherboards consisting of a master 3 and three slaves 4, 5, 6, each with a first edge and a second edge opposite the first edge. Within the cabinet, the master motherboard 3 is mounted on the frame vertically, perpendicular to a back panel 8 of the cabinet with its first edge adjacent the back panel. The first slave motherboard 4 is mounted on the frame vertically, parallel to the back panel 8 and adjacent to the second edge of the master 3 and an upper side of the cabinet. The second slave motherboard 5 is mounted on the frame vertically, parallel to the back panel 8 and the first slave 4, and at the same height as the first slave. The third slave motherboard 6 is mounted on the frame horizontally at a base of the cabinet and below the first and second slaves 4, 5. Each motherboard may have an attached ventilator 11 extending in a perpendicular direction to the motherboard to which it is attached in order to provide
