Three Main Types Of Expansion Slots

These computer cases also can have as many as nine expansion card slots, with room for an ATX-XL motherboard. Home Theater Computer Case: An “HTPC” can be a great addition to your custom home theater.

  • Notebook and other portable computers have a special type of expansion slot used for installing a PC Card, which is a thin credit card-sized device that adds memory, disk drives, sound, fax/modem, and communications capabilities to a mobile computer.
  • The different types of ATX are known as micro-ATX (sometimes shown as µATX, mini-ATX, FlexATX, EATX, WATX, nano-ATX, pico-ATX, and mobileATX). A smaller form factor is ITX, which comes in mini-ITX, nano-ITX, and pico-ITX sizes.

Unlike the other slots, where you can plug a card into any compatible slot, this one is for video cards only. There have been several different video card slot types over the years. Mail to hong kong. On a modern computer there are only three common types, from least to most common they are PCI, AGP and PCI-E slots. Besides the main types of computer buses, there are some expansion types of computer buses. These expansion types generally include ISA, EISA, MCA, VESA, PCI, PCMCIA, AGP, and SCSI. The most commonly used type of expansion bus is of ISA and it was originally patterned to for usage in the IBM pc.

In computing, the 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.

3 Types Of Expansion Slots

  • 2Comparisons
  • 5Mini PC

Overview of form factors[edit]

Comparison of some common motherboard form factors

A PC motherboard is the main circuit board within a typical desktop computer, laptop or server. Its main functions are as follows:

  • To serve as a central backbone to which all other modular parts such as CPU, RAM, and hard drives can be attached as required to create a computer
  • To be interchangeable (in most cases) with different components (in particular CPU and expansion cards) for the purposes of customization and upgrading
  • To distribute power to other circuit boards
  • To electronically co-ordinate and interface the operation of the components

As new generations of components have been developed, the standards of motherboards have changed too. For example, the introduction of AGP and, more recently, PCI Express have influenced motherboard design. However, the standardized size and layout of motherboards have changed much more slowly and are controlled by their own standards. The list of components required on a motherboard changes far more slowly than the components themselves. For example, north bridge microchips have changed many times since their introduction with many manufacturers bringing out their own versions, but in terms of form factor standards, provisions for north bridges have remained fairly static for many years.

Although it is a slower process, form factors do evolve regularly in response to changing demands. IBM's long-standing standard, AT (Advanced Technology), was superseded in 1995 by the current industry standard ATX (Advanced Technology Extended), which still governs the size and design of the motherboard in most modern PCs. The latest update to the ATX standard was released in 2007. A divergent standard by chipset manufacturer VIA called EPIA (also known as ITX, and not to be confused with EPIC) is based upon smaller form factors and its own standards.

Differences between form factors are most apparent in terms of their intended market sector, and involve variations in size, design compromises and typical features. Most modern computers have very similar requirements, so form factor differences tend to be based upon subsets and supersets of these. For example, a desktop computer may require more sockets for maximum flexibility and many optional connectors and other features on board, whereas a computer to be used in a multimedia system may need to be optimized for heat and size, with additional plug-in cards being less common. The smallest motherboards may sacrifice CPU flexibility in favor of a fixed manufacturer's choice.

Comparisons[edit]

Tabular information[edit]

Form factorOriginatedMax. size[info 1]
width × depth
Notes
(typical usage, Market adoption, etc.)
XTIBM 19838.5 × 11 in
216 × 279 mm
Obsolete, see Industry Standard Architecture. The IBM Personal Computer XT was the successor to the original IBM PC, its first home computer. As the specifications were open, many clone motherboards were produced and it became a de facto standard.
AT (Advanced Technology)IBM 198412 × 11–13 in
305 × 279–330 mm
Obsolete, see Industry Standard Architecture. Created by IBM for the IBM Personal Computer/AT, an Intel 80286 machine. Also known as Full AT, it was popular during the era of the Intel 80386 microprocessor. Superseded by ATX.
Baby-ATIBM 19858.5 × 10–13 in
216 × 254–330 mm
IBM's 1985 successor to the AT motherboard. Functionally equivalent to the AT, it became popular due to its significantly smaller size.
ATXIntel 199512 × 9.6 in
305 × 244 mm
Created by Intel in 1995. As of 2017, it is the most popular form factor for commodity motherboards. Typical size is 9.6 × 12 in although some companies extend that to 10 × 12 in.
SSI CEBSSI12 × 10.5 in
305 × 267 mm
Created by the Server System Infrastructure (SSI) forum. Derived from the EEB and ATX specifications. This means that SSI CEB motherboards have the same mounting holes and the same IO connector area as ATX motherboards.
SSI EEBSSI12 × 13 in
305 × 330 mm
Created by the Server System Infrastructure (SSI) forum. Derived from the EEB and ATX specifications. This means that SSI CEB motherboards have the same mounting holes and the same IO connector area as ATX motherboards, but SSI EEB motherboards do not.
SSI MEBSSI16.2 × 13 in
411 × 330 mm
Created by the Server System Infrastructure (SSI) forum. Derived from the EEB and ATX specifications.
microATX19969.6 × 9.6 in
244 × 244 mm
A smaller variant of the ATX form factor (about 25% shorter). Compatible with most ATX cases, but has fewer slots than ATX, for a smaller power supply unit. Very popular for desktop and small form factor computers as of 2017.
Mini-ATXAOpen 20055.9 × 5.9 in
150 × 150 mm
Mini-ATX is considerably smaller than Micro-ATX. Mini-ATX motherboards were designed with MoDT (Mobile on Desktop Technology) which adapt mobile CPUs for lower power requirement, less heat generation and better application capability.
FlexATXIntel 19999.0 × 7.5 in
228.6 × 190.5 mm max.
A subset of microATX developed by Intel in 1999. Allows more flexible motherboard design, component positioning and shape. Can be smaller than regular microATX.
Mini-ITXVIA 20016.7 × 6.7 in
170 × 170 mm max.
A small, highly integrated form factor, designed for small devices such as thin clients and set-top boxes.
Nano-ITXVIA 20034.7 × 4.7 in
120 × 120 mm
Targeted at smart digital entertainment devices such as PVRs, set-top boxes, media centers and Car PCs, and thin devices.
Pico-ITXVIA 20073.9 × 2.8 in
100 × 72 mm max.
Mobile-ITXVIA 20072.953 × 1.772 in
75 × 45 mm
Neo-ITXVIA 2012170 × 85 × 35 mmUsed in the VIA Android PC
Mini-STXIntel 2015147 x 140 mmSmaller than Mini-ITX, but bigger than the NUC, this board is used in small form factor computers, using a socketed intel core processor and SO-DIMMS.
BTX (Balanced Technology Extended)Intel 200412.8 × 10.5 in
325 × 267 mm max.
A standard proposed by Intel as a successor to ATX in the early 2000s, according to Intel the layout has better cooling. BTX Boards are flipped in comparison to ATX Boards, so a BTX or MicroBTX Board needs a BTX case, while an ATX style board fits in an ATX case. The RAM slots and the PCI slots are parallel to each other.

Processor is placed closest to the fan. May contain a CNR board.

MicroBTX (or uBTX)Intel 200410.4 × 10.5 in
264 × 267 mm max.
MicroBTX (also called uBTX) is a computer motherboard form factor. A microBTX is 10.4 × 10.5 in (264 × 267 mm) and can support up to four expansion slots.
PicoBTXIntel 20048.0 × 10.5 in
203 × 267 mm max.
DTXAMD 20078.0 × 9.6 in
200 × 244 mm max.
smartModuleDigital-Logic66 × 85 mmUsed in embedded systems and single board computers. Requires a baseboard.
ETXKontron95 × 114 mmUsed in embedded systems and single board computers. Requires a baseboard.
COM Express BasicPICMG95 × 125 mmUsed in embedded systems and single board computers. Requires a carrier board. Formerly referred to as ETXexpress by Kontron.
COM Express CompactPICMG95 × 95 mmUsed in embedded systems and single board computers. Requires a carrier board. Formerly referred to as microETXexpress by Kontron.
COM Express MiniPICMG55 × 84 mmUsed in embedded systems and single board computers. Requires a carrier board. Formerly referred to as nanoETXexpress by Kontron. Also known as COM Express Ultra and adheres to pin-outs Type 1 or Type 10[1]
CoreExpressSFF-SIG58 × 65 mmUsed in embedded systems and single board computers. Requires a carrier board.
Extended ATX (EATX)Unknown12 × 13 in
305 × 330 mm
Used in rackmount server systems. Typically used for server-class type motherboards with dual processors and too much circuitry for a standard ATX motherboard. The mounting hole pattern for the upper portion of the board matches ATX.
Enhanced Extended ATX (EEATX)Supermicro13.68 × 13 in
347 × 330 mm
Used in rackmount server systems. Typically used for server-class type motherboards with dual processors and too much circuitry for a standard E.ATX motherboard.
LPXWestern Digital 9 × 11–13 in
229 × 279–330 mm
Based on a design by Western Digital, it allowed smaller cases than the AT standard, by putting the expansion card slots on a Riser card. Used in slimline retail PCs. LPX was never standardized and generally only used by large OEMs.
Mini-LPXWestern Digital 8–9 × 10–11 in
203–229 × 254–279 mm
Used in slimline retail PCs.
PC/104PC/104 Consortium 19923.8 × 3.6 inUsed in embedded systems. AT Bus (ISA) architecture adapted to vibration-tolerant header connectors.
PC/104-PlusPC/104 Consortium 19973.8 × 3.6 inUsed in embedded systems. PCI Bus architecture adapted to vibration-tolerant header connectors.
PCI/104-ExpressPC/104 Consortium 20083.8 × 3.6 inUsed in embedded systems.
PCI Express architecture adapted to vibration-tolerant header connectors.
PCIe/104PC/104 Consortium 20083.8 × 3.6 inUsed in embedded systems.
PCI/104-Express without the legacy PCI bus.
NLXIntel 19998–9 × 10–13.6 in
203–229 × 254–345 mm
A low-profile design released in 1997. It also incorporated a riser for expansion cards,[2] and never became popular.
UTXTQ-Components 200188 × 108 mmUsed in embedded systems and IPCs. Requires a baseboard.
WTXIntel 199814 × 16.75 in
355.6 × 425.4 mm
A large design for servers and high-end workstations featuring multiple CPUs and hard drives.
SWTXSupermicro16.48 × 13 in
418 × 330 mm
A proprietary design for servers and high-end workstations featuring multiple CPUs.
HPTXEVGA 200813.6 × 15 in
345.44 × 381 mm
A large design by EVGA currently featured on two motherboards; the eVGA SR2 and SRX. Intended for use with multiple CPUs. Cases require 9 expansion slots to contain this form-factor.
XTX200595 × 114 mmUsed in embedded systems. Requires a base.
  1. ^For boards which take expansion slots, the length of the expansion card aligns with the depth of the system board. The case may support cards longer than the depth of the mainboard.

Maximum number of expansion card slots[edit]

ATX case compatible:

Different Types Of Slot Machines

SpecificationNumber
HPTX9
ATX/EATX/SSI EEB/SSI CEB7
MicroATX4
FlexATX3
DTX/Mini-DTX2
Mini-ITX1

Visual examples of different form factors[edit]

  • Different form factors
  • ATX
    (Abit KT7)

  • mini-ITX
    (VIA EPIA 5000AG)

  • Pico-ITX
    (VIA EPIA PX10000G)

PC/104 and EBX[edit]

PC/104 is an embedded computer standard which defines both a form factor and computer bus. PC/104 is intended for embedded computing environments. Single board computers built to this form factor are often sold by COTS vendors, which benefits users who want a customized rugged system, without months of design and paper work.

The PC/104 form factor was standardized by the PC/104 Consortium in 1992.[3] An IEEE standard corresponding to PC/104 was drafted as IEEE P996.1, but never ratified.[4]

The 5.75 × 8.0 in Embedded Board eXpandable (EBX) specification, which was derived from Ampro's proprietary Little Board form-factor, resulted from a collaboration between Ampro and Motorola Computer Group.

As compared with PC/104 modules, these larger (but still reasonably embeddable) SBCs tend to have everything of a full PC on them, including application oriented interfaces like audio, analog, or digital I/O in many cases. Also it's much easier to fit Pentium CPUs, whereas it's a tight squeeze (or expensive) to do so on a PC/104 SBC. Typically, EBX SBCs contain: the CPU; upgradeable RAM subassemblies (e.g., DIMM); Flash memory for solid state drive; multiple USB, serial, and parallel ports; onboard expansion via a PC/104 module stack; off-board expansion via ISA and/or PCI buses (from the PC/104 connectors); networking interface (typically Ethernet); and video (typically CRT, LCD, and TV).

Mini PC[edit]

Mini PC is a PC small form factor very close in size to an external CD or DVDdrive. Mini PCs have proven popular for use as HTPCs.

Examples[edit]

  • AOpenXC mini
  • Gigabyte Brix
  • Zotac ZBOX
  • Asus Vivopc

See also[edit]

References[edit]

  1. ^'Atom module shrinks to nano size'. Archived from the original on 2012-05-24. Retrieved 2009-12-30.
  2. ^'Form Factors Rev 1.3 :: NLX' Motherboards.org
  3. ^'PC/104 Embedded Consortium's History'. Archived from the original on 2008-02-11. Retrieved 2008-01-29.
  4. ^Angel, Jonathan (2010-02-01). 'Open standard defines tiny expansion modules'. LinuxDevices.com. Retrieved 2014-03-18.
Three Main Types Of Expansion Slots

External links[edit]

Retrieved from 'https://en.wikipedia.org/w/index.php?title=Computer_form_factor&oldid=929603703'

When you decide to expand your PC with a new device, you need to understand the expansion slots on your PC’s motherboard so you can determine what type of new device to buy. There are a bunch of different expansion slot standards and variations.

The two most common slots available on today’s PCs are PCI and PCI-Express:

Three main types of expansion slots free

PCI: The Peripheral Component Interconnect type of slot is the most popular and widely available expansion slot on today’s PCs. It’s normally colored white, though often beige is used. There are 32-bit and 64-bit PCI expansion slots.

PCIExpress: The latest rendition of the PCI standard is PCI-Express. PCI-Express slots are generally colored black or dark gray or sometimes even yellow. They also feature a variety of sizes.

Older expansion standards include

PCI-X: The PCI Extended standard was developed to improve on PCI, but as a standard PCI-Express superseded it. Some older PCs may still feature the PCI-X slot, which looks like a standard PCI slot but is considerably longer.

Three Types Of Expansion Slots

Be careful not to confuse PCI-X with PCI-Express! They’re different standards, different slots, and different expansion card types.

AGP: The Accelerated Graphics Port slot was designed specifically to handle high-end graphics adapters. It may still be found on older PCs, but today’s systems use PCI-Express expansion slots to handle high-end graphics adapters. AGP slots were often colored maroon and had a hinged hook on one end to help anchor the AGP card.

ISA: The original expansion slot for the PC family was ISA, which simply stood for Industry Standard Architecture (because the expansion slot lacked an official and suitably technical-sounding name). It had two varieties: 16-bit and a longer 16-bit version. An older Windows XP system may still sport an ISA slot, but few (if any) relevant ISA expansion cards are available today.

Sadly, without opening the case, there’s no way to determine what type of slots are present on your PC’s motherboard, let alone whether the slots are available (or empty). The only way to know for certain is to open the case and have a look.

Computer Expansion Slot Types

  • When the PC’s motherboard features a variety of slots, and you have a choice, choose a PCI-Express expansion card first.

  • Expansion slots are keyed: The edge connector on the expansion card cannot be plugged in backward. Of course, most expansion cards feature a rear slot mount, which means that you have to be determined to plug an expansion card in backward in the first place!

  • You can look on the back of your PC and examine the slot covers to determine whether a slot is empty. A blank slot cover, however, may not indicate that an expansion slot is available, because some expansion cards may not use the slot cover. Also, some expansion cards are double-wide and may render useless any empty expansion slots next to them.

  • Even though the expansion slots are all standardized, expansion cards come in different lengths. You can find full-length cards, half-size cards, and others. Smaller PC consoles may have room for only smaller expansion cards, or perhaps some expansion slots are limited to hosting only shorter expansion cards. Knowing this type of information before you buy an expansion card will prove to be a boon to your self-esteem.

  • PCI-X also featured two sets of voltages for expansion cards: 5 volts and 3.3 volts. Special notches in the expansion cards prevented the wrong slot from being used, but the differing voltages were still an issue for choosing the proper PCI-X expansion card.