In computing, an expansion card is a printed circuit board that can be inserted into an electrical connector, or expansion slot on a computer's motherboard to add functionality to a computer system. Sometimes the design of the computer's case and motherboard involves placing most of these slots onto a separate, removable card. Typically such cards are referred to as a riser card in part because they project upward from the board and allow expansion cards to be placed above and parallel to the motherboard.
PCI Express, officially abbreviated as PCIe or PCI-e, is a high-speed serial computer expansion bus standard, designed to replace the older PCI, PCI-X and AGP bus standards. It is the common motherboard interface for personal computers' graphics cards, sound cards, hard disk drive host adapters, SSDs, Wi-Fi and Ethernet hardware connections. PCIe has numerous improvements over the older standards, including higher maximum system bus throughput, lower I/O pin count and smaller physical footprint, better performance scaling for bus devices, a more detailed error detection and reporting mechanism, and native hot-swap functionality. More recent revisions of the PCIe standard provide hardware support for I/O virtualization.
A single-board computer (SBC) is a complete computer built on a single circuit board, with microprocessor(s), memory, input/output (I/O) and other features required of a functional computer. Single-board computers are commonly made as demonstration or development systems, for educational systems, or for use as embedded computer controllers. Many types of home computers or portable computers integrate all their functions onto a single printed circuit board.
Serial Peripheral Interface (SPI) is a de facto standard for synchronous serial communication, used primarily in embedded systems for short-distance wired communication between integrated circuits.
Mini-ITX is a 170 mm × 170 mm motherboard form factor developed by VIA Technologies in 2001. Mini-ITX motherboards have been traditionally used in small-configured computer systems. Originally, Mini-ITX was a niche standard designed for fanless cooling with a low power consumption architecture, which made them useful for home theater PC systems, where fan noise can detract from the cinema experience.
BTX is a form factor for motherboards, originally intended to be the replacement for the aging ATX motherboard form factor in late 2004 and early 2005.
PC/104 is a family of embedded computer standards which define both form factors and computer buses by the PC/104 Consortium. Its name derives from the 104 pins on the interboard connector (ISA) in the original PC/104 specification and has been retained in subsequent revisions, despite changes to connectors. PC/104 is intended for specialized environments where a small, rugged computer system is required. The standard is modular, and allows consumers to stack together boards from a variety of COTS manufacturers to produce a customized embedded system.
Small form factor is a term used for desktop computers and for some of their components, chassis and motherboard, to indicate that they are designed in accordance with one of several standardized form factors intended to minimize the volume and footprint of a desktop computer compared to the standard ATX form factor.
ETX, standing for Embedded Technology eXtended, is an integrated and compact 95 × 125 mm (3.7 × 4.9 in) computer-on-module (COM) form factor, which can be used in a design application much like an integrated circuit component. Each ETX COM integrates core CPU and memory functionality, the common I/O of a PC/AT, USB, audio, graphics, and Ethernet. All I/O signals as well as a full implementation of ISA and PCI buses are mapped to four high-density, low-profile connectors on the bottom side of the module.
In computer design, Pico-ITX is a PC motherboard form factor announced by VIA Technologies in January 2007 and demonstrated later the same year at CeBIT. The formfactor was transferred over to SFF-SIG in 2008. The Pico-ITX form factor specifications call for the board to be 10 × 7.2 cm (3.9 × 2.8 in), which is half the area of Nano-ITX.
In computing, the motherboard form factor is the specification of a motherboard – the dimensions, power supply type, location of mounting holes, number of ports on the back panel, etc. Specifically, in the IBM PC compatible industry, standard form factors ensure that parts are interchangeable across competing vendors and generations of technology, while in enterprise computing, form factors ensure that server modules fit into existing rackmount systems. Traditionally, the most significant specification is for that of the motherboard, which generally dictates the overall size of the case. Small form factors have been developed and implemented.
Universal EXTension (UEXT) is a connector layout which includes power and three serial buses: Asynchronous, I2C, and SPI separately over 10 pins in a 2x5 layout. The connector layout was specified by Olimex Ltd and declared an open-project that is royalty-free in 2011, and was used in all their boards after 2004.
Stackable Unified Module Interconnect Technology (SUMIT) is a connector between expansion buses independent of motherboard form factor. Boards featuring SUMIT connectors are usually used in "stacks" where one board sits on top of another. It was published by the Small Form Factor Special Interest Group.
Pico-ITXe is a PC Pico-ITX motherboard specification created by VIA Technologies and SFF-SIG. It was announced by VIA Technologies on October 29, 2008, and released in December 2008. The Pico-ITXe specifications call for the board to be 10 × 7.2 cm (3.9 × 2.8 in), which is half the area of Nano-ITX, and 12 layers deep. The processor can be a VIA C7 that uses VIA's NanoBGA2 technology. It uses DDR2 667/533 SO-DIMM memory, with support for up to 2GB. Video is supplied by VIA's Chrome9 HC3 GPU with built-in MPEG-2, 4, WMV9, and VC1 decoding acceleration. The BIOS is a 4 or 8 Mbit Award BIOS.
ESMexpress is a very compact computer-on-module (COM) standard. It is a complete processor module that currently supports several low-power Intel and PowerPC platforms. Apart from a CPU component, every module also includes memory and a range of serial communication interfaces such as PCI Express, Gigabit Ethernet, USB, SATA, SDVO, LVDS and HD audio. These interfaces are defined in the form factor's specification, and signals are assigned to two 120-pin connectors. This fixed pin mapping ensures that different ESMexpress modules can be exchanged more easily. Consequently, ESMexpress typically does not have an onboard FPGA. The idea behind this is to implement very specialized functions in an FPGA on the COM's carrier board to ease upgrades of the system CPU through exchange of the ESMexpress module.
CoreExpress modules are complete computer-on-module (COM) highly integrated, compact computers that can be used in an embedded computer board design, much like an integrated circuit component. COMs integrate CPU, memory, graphics, and BIOS, and common I/O interfaces. The interfaces are modern, using only digital buses such as PCI Express, Serial ATA, Ethernet, USB, and HD audio. All signals are accessible on a high-density, high-speed, 220-pin connector. Although most implementations use Intel processors, the specification is open for different CPU modules.
Qseven, a computer-on-module (COM) form factor, is a small, highly integrated computer module that can be used in a design application much like an integrated circuit component. It is smaller than other computer-on-module standards such as COM Express, ETX or XTX and is limited to very low power consuming CPUs. The maximum power consumption should be no more than 12 watts.
The PCI/104-Express specification establishes a standard to use the high-speed PCI Express bus in embedded applications. It was developed by the PC/104 Consortium and adopted by member vote in March 2008. PCI Express was chosen because of its market adoption, performance, scalability, and growing silicon availability worldwide. It provides a new high-performance physical interface while retaining software compatibility with the existing PCI infrastructure.
Smart Mobility Architecture (SMARC) is a computer hardware standard for computer-on-modules (COMs). SMARC modules are specifically designed for the development of extremely compact low-power systems, such as mobile devices.
M.2, pronounced m dot two and formerly known as the Next Generation Form Factor (NGFF), is a specification for internally mounted computer expansion cards and associated connectors. M.2 replaces the Mini-SATA (mSATA) standard, which uses the PCI Express Mini Card physical card layout and connectors. Employing a more flexible physical specification, M.2 allows different module widths and lengths, which, paired with the availability of more advanced interfacing features, makes M.2 more suitable than mSATA in general for solid-state storage applications, particularly in smaller devices such as ultrabooks and tablets.
