Coldplug

Computer components are usually described as cold-pluggable if the computer system must be powered down to add or remove them. The opposite term is hotpluggable; hotpluggable components can be added or removed without powering down the computer.

In most computer systems, CPUs and memory are coldpluggable, but it is common for high-end servers and mainframes to feature hotplug capability of these components.

Sometimes, devices that would be hot-pluggable may appear to only be cold-pluggable because of deficiencies in the system software. For example, PS/2 pointer devices are generally hot-pluggable (although they are not designed to be), but Microsoft Windows 95 and related operating systems would commonly have to be rebooted every time a PS/2 mouse was replaced, in order to detect the new mouse.

As mentioned in the article on hot swap, the terms hot plug and cold plug, can be taken to mean two different things, depending on the context. In a more generic context, hot plug is the ability to add or remove hardware without powering down the system, while cold plug is the inability to do so. In the context of comparing certain hot-pluggable devices, however, hot plug can be taken to mean the ability of the system to autonomously detect the addition or removal of hardware as it occurs, while cold plug can be taken to mean the ability to add or remove devices without powering down or rebooting the system, but the inability of the system to detect these changes, in which case the system operator would have to tell the system software that the change has occurred.