Editing ATX (section)

== Variants ==
{{redirect|EATX|the electronic automatic transaxle|automatic transmission}}
{{Disputed section | E-ATX is not a form factor|date=April 2020}}
[[File:ATX ITX AT Motherboard Compatible Dimensions.svg|thumb|ATX, [[Mini-ITX]], and AT motherboard compatible dimensions and bore positions]]
[[File:Form Factor dimension.png|thumb|ATX motherboard size comparison; rear is on left.
{{legend|#57ccff|[[microATX]] {{nowrap|({{convert|9.6|xx|9.6|in|mm|0|disp=output only|abbr=on}})}}}}
{{legend|#ffffff|Standard ATX {{nowrap|({{convert|12|xx|9.6|in|mm|0|disp=output only|abbr=on}})}}}}
{{legend|#e6ff24|Ultra ATX {{nowrap|({{convert|14.4|xx|9.6|in|mm|0|disp=output only|abbr=on}})}}}}
{{legend|#336aff|Extended ATX (EATX) {{nowrap|({{convert|12|xx|13|in|mm|0|disp=output only|abbr=on}})}}}}
{{legend|#f02700|[[WTX (form factor)|WTX]] {{nowrap|({{convert|14|xx|16.75|in|mm|0|disp=output only|abbr=on}})}}}}
{{legend|#3aff48|[[SSI CEB|SSI MEB]] {{nowrap|({{convert|16.2|xx|13|in|mm|0|disp=output only|abbr=on}})}}}}]]
Several ATX-derived designs have been specified that use the same power supply, mountings and basic back panel arrangement, but set different standards for the size of the board and number of expansion slots. Standard ATX provides seven slots at {{convert|0.8|in|mm|0|abbr=on}} spacing; the popular [[microATX]] size removes {{convert|2.4|in|mm}} and three slots, leaving four. Here width refers to the distance along the external connector edge, while depth is from front to rear. Note each larger size inherits all previous (smaller) colors area.

[[AOpen]] has conflated the term [[Mini ATX]] with a more recent{{when|date=September 2022}} {{convert|15|xx|15|cm|in|1|abbr=on}} design. Since references to Mini ATX have been removed from ATX specifications since the adoption of microATX, the AOpen definition is the more contemporary term and the one listed above is apparently only of historical significance. This sounds contradictory to the now common Mini-ITX standard ({{convert|17|xx|17|cm|in|1|abbr=on}}), which is a potential source of confusion. A number of manufacturers have added one to three additional expansion slots (at the standard 0.8 inch spacing) to the standard 12-inch ATX motherboard width.

Form factors considered obsolete in 1999 included Baby-AT, full size AT, and the semi-proprietary LPX for low-profile cases. Proprietary motherboard designs such as those by Compaq, Packard-Bell, Hewlett Packard and others existed, and were not interchangeable with multi-manufacturer boards and cases. Portable and notebook computers and some 19-inch rackmount servers have custom motherboards unique to their particular products.<ref>Scott Mueller, ''Upgrading and Repairing PCs, Eleventh Edition'', Que Books, 1999, {{ISBN|0-7897-1903-7}}, page 1255</ref>

{| class="wikitable sortable" style="text-align:center;"
|-
! Form factor
! Originated
! Date
! Max. size{{efn|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.}}<br />depth × width
! Slots
! Notes<br />(typical usage, market adoption, etc.)
|-
! ATX
| Intel
| 1995
| 12&nbsp;×&nbsp;9.6&nbsp;in (305&nbsp;×&nbsp;244&nbsp;mm)
| 7{{efn|Most common ATX motherboards have 6 slots despite having the physical sizing for 7 slots.}}
| Original, successor to AT motherboard
|-
| ''Proprietary, specific to crypto-mining specific motherboards''
| {{unk}}
| 2011
| 12&nbsp;×&nbsp;8&nbsp;in (305&nbsp;×&nbsp;203&nbsp;mm)
| 3
| 3 double-slot add-in cards with 1 slots of free space in between
|-
! [[SSI CEB]]
| [[SSI CEB|SSI]]
| {{dunno}}
| 12&nbsp;×&nbsp;10.5 in (305&nbsp;×&nbsp;267&nbsp;mm)
| 7
| Compact Electronics Bay
|-
! [[SSI CEB|SSI MEB]]
| SSI
| 2011
| 16.2&nbsp;×&nbsp;13&nbsp;in (411&nbsp;×&nbsp;330&nbsp;mm)
| 12
| Midrange Electronics Bay
|-
! [[SSI CEB|SSI EEB]]
| SSI
| {{dunno}}
| 12&nbsp;×&nbsp;13&nbsp;in (305&nbsp;×&nbsp;330&nbsp;mm)
| 7
| Enterprise Electronics Bay
|-
! [[SSI CEB|SSI TEB]]
| SSI
| {{dunno}}
| 12&nbsp;×&nbsp;10.5&nbsp;in (305&nbsp;×&nbsp;267&nbsp;mm)
| 7
| Thin Electronics Bay, for rack-mount, has board component height specification
|-
! [[microATX]]
| Intel
| 1997
| 9.6&nbsp;×&nbsp;9.6&nbsp;in (244&nbsp;×&nbsp;244&nbsp;mm)
| 4
| Fits in ATX, and EATX cases.
|-
! [[FlexATX]]
| Intel
| 1997
| 9&nbsp;×&nbsp;7.5&nbsp;in (229&nbsp;×&nbsp;191&nbsp;mm)
| 3
|
|-
! Extended ATX (standard)
| Supermicro / [[Asus]]
| {{dunno}}
| 12&nbsp;×&nbsp;13&nbsp;in (305&nbsp;×&nbsp;330&nbsp;mm)
| 7
| Screw holes not completely compatible with some ATX cases. Intended for two CPU sockets.
|-
! Extended ATX (commonly)
| {{unk}}
| {{dunno}}
| 12&nbsp;×&nbsp;10.1&nbsp;in (305&nbsp;×&nbsp;257&nbsp;mm)<br />12&nbsp;×&nbsp;10.4&nbsp;in (305&nbsp;×&nbsp;264&nbsp;mm)<br />12&nbsp;×&nbsp;10.5&nbsp;in (305&nbsp;×&nbsp;267&nbsp;mm)<br />12&nbsp;×&nbsp;10.7&nbsp;in (305&nbsp;×&nbsp;272&nbsp;mm)
| 7
| ATX pattern screw holes
|-
! EE-ATX
|Supermicro
| {{dunno}}
| 13.68&nbsp;×&nbsp;13&nbsp;in (347&nbsp;×&nbsp;330&nbsp;mm)
| 7
| Enhanced Extended ATX
|-
! Ultra ATX
| Foxconn
| 2008
| 14.4&nbsp;×&nbsp;9.6&nbsp;in (366&nbsp;×&nbsp;244&nbsp;mm)<ref>{{Cite web|url=http://www.tomshardware.com/news/ces-foxconn-x48-shimano,4677.html|title=Foxconn Reveals X48, Ultra ATX, and Shamino|date=13 January 2008}}</ref>
| 10
| Intended for multiple double-slot video cards, and dual CPUs.
|-
! XL-ATX
| [[EVGA Corporation|EVGA]] 
| 2009
| 13.5&nbsp;×&nbsp;10.3&nbsp;in (343&nbsp;×&nbsp;262&nbsp;mm)
| 9
|
|-
! XL-ATX
| Gigabyte 
| 2010
| 13.58&nbsp;x&nbsp;10.31&nbsp;in (345&nbsp;x&nbsp;262&nbsp;mm)
| 7
|
|-
! XL-ATX
| [[Micro-Star International|MSI]] 
| 2010
| 13.6&nbsp;× 10.4&nbsp;in (345&nbsp;×&nbsp;264&nbsp;mm)
| 7
|
|-
! [[WTX (form factor)|WTX]]
| Intel
| 1998
| 14&nbsp;×&nbsp;16.75&nbsp;in (356&nbsp;×&nbsp;425&nbsp;mm).
| 9
| Discontinued 2008
|-
! [[Mini-ITX]]
| [[VIA Technologies|VIA]]
| 2001
| 6.7&nbsp;x&nbsp;6.7in (170&nbsp;×&nbsp;170&nbsp;mm).
| 1
| Originally designed for home theatre or other fanless applications
|-
! [[DTX (form factor)|Mini-DTX]]
| [[Advanced Micro Devices|AMD]]
| 2007
| 8&nbsp;×&nbsp;6.7&nbsp;in (203&nbsp;×&nbsp;170&nbsp;mm)
| 2
| Derived from Mini-ITX and DTX
|-
! [[BTX (form factor)|BTX]]
| Intel
| 2004
| 12.8&nbsp;×&nbsp;10.5&nbsp;in (325&nbsp;×&nbsp;267&nbsp;mm)
| 7
| Canceled 2006. Also micro, nano, and pico variants. Not generally compatible with ATX mounting.
|-
! HPTX
| EVGA
| 2010
| 13.6&nbsp;×&nbsp;15&nbsp;in (345&nbsp;×&nbsp;381&nbsp;mm)
| 6
| Dual processors, 12 RAM slots
|-
! [[SWTX]]
| Supermicro
| 2006
| 16.48&nbsp;×&nbsp;13&nbsp;in (419&nbsp;×&nbsp;330&nbsp;mm)<br />and others
| 5
| Quad processors, not compatible with ATX mounting
|-
! YTX
| [[Asus]], [[Micro-Star International|MSI]] <br />& Maxsun
| 2023
| 6.89&nbsp;×&nbsp;9.65&nbsp;in (175&nbsp;×&nbsp;245&nbsp;mm)
| 1
| New form factor supporting the DIY-APE initiative
|}

Although true E-ATX is {{convert|12|xx|13|in|mm|0|abbr=on}} most motherboard manufacturers also refer to motherboards with measurements {{convert|12|xx|10.1|in|mm|0|abbr=on}}, {{convert|12|xx|10.4|in|mm|0|abbr=on}}, {{convert|12|xx|10.5|in|mm|0|abbr=on}} and {{convert|12|xx|10.7|in|mm|0|abbr=on}} as E-ATX. While E-ATX and SSI EEB (Server System Infrastructure (SSI) Forum's Enterprise Electronics Bay (EEB)) share the same dimensions, the screw holes of the two standards do not all align; rendering them incompatible.{{Citation needed|date=April 2020}}

In 2008, [[Foxconn]] unveiled a Foxconn F1 motherboard prototype, which has the same width as a standard ATX motherboard, but an extended 14.4" length to accommodate 10 slots.<ref>{{cite web |url=http://www.hardwaresecrets.com/article/513 |title=Foxconn F1 Motherboard Prototype |publisher=Hardwaresecrets.com |access-date=18 November 2014 |url-status=dead |archive-url=https://web.archive.org/web/20141024000823/http://www.hardwaresecrets.com/article/513 |archive-date=24 October 2014 }}</ref> The firm called the new {{convert|14.4|xx|9.6|in|mm|0|abbr=on}} design of this motherboard "Ultra ATX"<ref>{{cite web |url=http://www.tomshardware.com/news/ces-foxconn-x48-shimano,4677.html |title=Foxconn Reveals X48, Ultra ATX, and Shamino |author=Thomas Soderstrom|work=Tom's Hardware|date=13 January 2008 |access-date=18 November 2014}}</ref> in its CES 2008 showing. Also unveiled during the January 2008 CES was the [[Lian Li]] Armorsuit PC-P80 case with 10 slots designed for the motherboard.<ref>{{cite web |url=http://www.techpowerup.com/reviews/LianLi/Armorsuit_PC-P80R_Spider_Edition |title=Lian Li Armorsuit PC-P80R Spider Edition|work=TechPowerUp |date=11 May 2008 |access-date=18 November 2014}}</ref>

The name "XL-ATX" has been used by at least three companies in different ways:

* In September 2009, [[EVGA Corporation]] had already released a {{convert|13.5|xx|10.3|in|mm|0|abbr=on}} "XL-ATX" motherboard as its ''EVGA X58 Classified 4-Way SLI'',<ref>{{cite web |url=https://www.evga.com/articles/00501/ |title=The New 4-Way SLI Platform Has Arrived! |publisher=Evga.com |access-date=18 November 2014}}</ref> which requires an Ultra-ATX sized case to support four "double-slot" graphics cards.<ref>{{Cite web| url=http://www.evga.com/products/moreInfo.asp?pn=170-BL-E762-A1&family=Motherboard | archive-url=https://web.archive.org/web/20110716165637/http://www.evga.com/products/prodlist.asp | title=Product list GeForce 500 Series | archive-date=2011-07-16}}</ref>
* Gigabyte Technology launched another XL-ATX motherboard, with model number GA-X58A-UD9 in 2010 measuring at {{convert|345|xx|262|mm|in|1|order=flip|abbr=on}}, and GA-X79-UD7 in 2011 measuring at {{convert|324|xx|253|mm|in|1|order=flip|abbr=on}}. In April 2010, Gigabyte announced its {{convert|12.8|xx|9.6|in|mm|0|abbr=on}} GA-890FXA-UD7 motherboard that allowed all seven slots to be moved downward by one slot position. The added length could have allowed placement of up to eight expansion slots, but the top slot position is vacant on this particular model.
* [[Micro-Star International|MSI]] released MSI X58 Big Bang in 2010, MSI P67 Big Bang Marshal in 2011, MSI X79 Xpower Big Bang 2 in 2012 and MSI Z87 Xpower in 2013 all of them are {{convert|345|xx|264|mm|in|1|order=flip|abbr=on}}. Although these boards have room for additional expansion slots (9 and 8 total, respectively), all three provide only seven expansion connectors; the topmost positions are left vacant to provide more room for the CPU, chipset and associated cooling.

In 2010, [[EVGA Corporation]] released a new motherboard, the "Super Record 2", or SR-2, whose size surpasses that of the "EVGA X58 Classified 4-Way SLI". The new board is designed to accommodate two Dual QPI LGA1366 socket CPUs (e.g. Intel [[Xeon]]), similar to that of the [[Intel Skulltrail]] motherboard that could accommodate two Intel Core&nbsp;2 Quad processors and has a total of seven PCI-E slots and 12 DDR3 RAM slots. The new design is dubbed "HPTX" and is {{convert|13.6|xx|15|in|mm|0|abbr=on}}.<ref>{{cite web|url=https://www.evga.com/articles/00537/ |title=EVGA Corporation Super Record 2 |publisher=Evga.com |access-date=18 November 2014}}</ref>