A typical barebone desktop system consists of a CPU, a computer case (or tower), with a pre-fitted motherboard and power supply.
Sometimes PCs with everything a normal desktop PC has except Microsoft Windows operating systems are sold as a barebone computer, but may include free software such as Linux.
As it leaves the factory, it contains only elements strictly tied to the computer's design (case, motherboard, display, keyboard, pointing device, etc.
), and the consumer or reseller has to add standardized off-the-shelf components such as CPU and GPU (when not integrated on the motherboard), memory, mass storage, WiFi card, etc.
[5] Future upgradeability of a barebone system may be limited, especially the motherboard component, which may have less space for extra I/O devices and fewer memory and PCI card slots than desired.
Shuttle SN41G2 (non-standard form factor). This series typically contains a custom-size motherboard and power supply, while CPU, memory and drives (2 HDD can be fitted) must be purchased separately. Graphics is usually added via
PCI-Express
expansion card (double width supported) but processor graphics, if present, is accessible. Processor cooling evolved from relying on the cooler that is sold with CPU till recently offered highly custom laptop-style heat sinks.
[
1
]
Supermicro 5016T-MTFB (
1U
server). CPU and memory slots are empty; also contains one (topmost) dummy fan that can be replaced by functional fan if required. While blue SATA cables to hard drives are installed (top edge), hard drives themselves are not included. The available PCI-Express slot (
riser card
in the middle) is also empty. Includes motherboard, CD-ROM and power supply (bottom).
[
2
]
Old
PCI
slot is still present on the motherboard but requires separately sold riser card to be reachable.
