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 more modularity, which allows for a 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.[7] 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.