A desktop replacement computer (DTR) is a personal computer that provides all the features of a desktop computer while staying mobile. These are often bigger and larger laptops or, in some cases, 2-in-1 PCs with a form factor and a tablet-like interface. Due to their increased size, this computer class typically includes more powerful components and a larger display than that typically used in small laptops and may have relatively little (if any) battery capacity. Some use a limited range of desktop components to provide better performance at the expense of battery life. They are sometimes referred to as desktops, a portmanteau for the words “desktop” and “notebook”, although the term is also applied to desktop replacement computers in general.
The early and mid-1980s notebooks, such as the CCMC Portal R2E, Osborne I, Kaypro II, Compaq Portable, and Commodore Executive 64 (SX-64), were the precursors to desktop replacement. . These computers contained the processor, the display, the floppy disk drive, and the power supply in a single case-like case. Similar to the performance of the desktop computers of the time, they were easily transportable and came with an attached keyboard that served as a protective cover when not in use. They could be used wherever space and an electrical outlet were available because they did not have a battery. The development of the shape of the laptop has given a new impetus to the development of the laptop. Many early laptops had limited features in the interest of portability, requiring mobility-limiting accessories such as external floppy drives or bullet-point pointing devices. One of the first laptops that could be used as a stand-alone computer was the EUROCOM 2100 based on the Intel 8088 processor architecture. It duplicated the functionality of desktop templates without the need for an external docking station. The development of the modern desktop replacement computer came with the realization that many laptops were used in a semi-permanent location, often staying connected to an external power source at any time. This suggested that there was a market for a laptop computer that would take advantage of the lower need for user portability, enabling higher performance components, greater scalability and higher quality displays. Desktop replacement computers are also often used with a port replicator, to take full advantage of office comfort.
Modern desktop replacements generally perform better than traditional laptop-style computers as their size allows the inclusion of more powerful components. The larger body means more efficient heat-dissipation, allowing manufacturers to use components that would otherwise overheat during normal use. Furthermore, their increased size allows for greater expandability and features, as well as larger and brighter displays. However, these advantages generally come at a price premium, with many computers in this class costing as much as two desktop computers with similar specifications. Using a laptop form factor, however, desktop replacements still often suffer from limitations similar to those of more mobile laptops. They usually lack the ability to accept standard PCIe expansion cards, somewhat limiting their expandability. While desktop replacements can offer better cooling than other laptops, they rarely dissipate heat efficiently enough to allow for high-end desktop-class components, and thus may not reach the same performance levels as desktop computers. Desktop replacement computers are, with a few exceptions, difficult to upgrade compared to desktop computers, with many of their major components (such as the display) integral to the design of the machine, and others (such as the CPU and GPU) often being hard to access and replace. A small segment of desktop replacements do not include a battery as a standard feature, while some do not include ExpressCard support. They have the same limitations on serviceability as laptops, and can rarely use identical components to a desktop computer.