What controls the CPU form factor?

The correct understanding of what controls the CPU form factor is closely tied to the socket type on the motherboard. Each CPU is designed to fit into a specific socket type, which is defined by the motherboard’s architecture. This socket is shaped and configured to accommodate a particular CPU, ensuring a proper connection and functionality.

The socket type dictates the physical and electrical interface between the CPU and the motherboard. This includes the arrangement of pins or pads that connect to the CPU, as well as the compatibility with specific generations or families of processors. Different CPU manufacturers and generations employ different socket types, which means that not all CPUs can be placed into every motherboard.

In considering the options, while the motherboard design itself can encompass various features that might influence the overall compatibility of components, it is predominantly the socket type that directly specifies the form factor for the CPU. The power supply unit and RAM configuration are important aspects of a computer system but do not play a role in defining the CPU's form factor. Therefore, recognizing the significance of the socket type provides clarity on how CPUs are supported within different motherboard designs.