Coldplug

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Coldplugging is often taken to mean the opposite of hotplugging. In other words, the inability of a computer system to add or remove hardware without powering the system down. Examples of devices that are coldpluggable include PCI (some PCI chipsets have hotplug support, however, but these are very expensive and almost exclusively used in server systems), ISA and PATA devices.

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 hotpluggable may appear to only be coldpluggable because of deficiencies in the system software. For example, PS/2 pointer devices are generally hotpluggable (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. (Windows XP now supports PS/2 pointer device hotswapping.)

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.