View source for BTX (form factor)

{{short description|Form factor for motherboards}}
[[File:Comparison BTX μBTX nanoBTX ITX picoBTX.svg|thumb|Comparison BTX μBTX nanoBTX ITX picoBTX]]
[[Image:BTX-Gehaeuse IMGP1405.jpg|right|thumb|BTX case of a Fujitsu Siemens Esprimo P2510]]
[[Image:BTX M-B IMG 1159.JPG|thumb|Clearly visible: the four holes for the "Support and Retention Module (SRM)"]]
'''BTX''' (for '''Balanced Technology eXtended''') is a [[form factor (design)|form factor]] for [[motherboard]]s, originally intended to be the replacement for the aging [[ATX]] [[motherboard form factor]] in late 2004 and early 2005.

It was designed to alleviate some of the issues that arose from using newer technologies (which often demand more power and create more heat) on motherboards compliant with the circa 1996 [[ATX]] specification. The ATX and BTX standards were both proposed by [[Intel]]. However, future development of BTX retail products by [[Intel]] was canceled in September 2006 following Intel's decision to refocus on low-power CPUs after suffering scaling and thermal issues with the [[Pentium 4]].

The first company to implement BTX was [[Gateway Inc]], followed by [[Dell]] and MPC.  The first generation of [[Apple Inc.|Apple's]] [[Mac Pro#1st generation (tower)|Mac Pro]] used some elements of the BTX design system as well, but was not BTX-compliant, instead using a proprietary form factor.

==Enhancements==
*''Low-profile''&nbsp;– With the push for ever-smaller systems, a redesigned backplane that shaves inches off height requirements is a benefit to [[system integrator]]s and enterprises who use [[rack mount]]s or [[blade server]]s.
*''Thermal design''&nbsp;– The BTX layout establishes a straighter path of airflow with fewer obstacles, resulting in better overall cooling capabilities. There is no dedicated CPU fan&nbsp;– instead, a large 12&nbsp;cm case fan is mounted, drawing its air directly from outside the computer and cooling the CPU through an airduct. Another distinct feature of BTX is the vertical mounting of the motherboard on the left-hand side. This results in the graphics card heatsink or fan facing upwards, rather than in the direction of the adjacent expansion card.
*''Structural design''&nbsp;– The BTX standard specifies different locations for hardware mounting points, thereby reducing [[latency (engineering)|latency]] between key components and also reduces the physical strain imposed on the motherboard by heat sinks, capacitors and other components dealing with electrical and thermal regulation. For example, the [[Northbridge (computing)|Northbridge]] and [[Southbridge (computing)|Southbridge]] chips are located near each other and to the hardware they control like CPU, RAM and expansion ports (PS/2, USB, LPT etc.)

===picoBTX===
[[File:BTXformFactor.JPG|right|thumb|BTX form factor motherboard inside a Dell Dimension E520]]
Pico BTX is a [[motherboard]] form factor that is meant to miniaturize the {{convert|12.8|xx|10.5|in|mm|0|abbr=on}} BTX standard. Pico BTX motherboards measure {{convert|8|xx|10.5|in|mm|0|abbr=on}}. This is smaller than many current "micro"-sized motherboards, hence the name  "[[pico-|pico]]". These motherboards share a common top half with the other sizes in the BTX line, but support only one or two expansion slots, designed for half-height or riser card applications.<ref name="Toms Hardware">http://www.tomshardware.com/reviews/beginners-guide-motherboard-selection,1289-5.html {{Dead link|date=February 2022}}</ref>

Other smaller BTX sizes include: [[microBTX]] at {{convert|10.4|xx|10.5|in|mm|0|abbr=on}} and nano BTX at {{convert|8.8|xx|10.5|in|mm|0|abbr=on}}.

{|  class=wikitable
|-
! align=left | Specification
! align=left | Year
! align=left | Dimensions of motherboard
! align=left | Expansion slots
|-
| BTX
| rowspan="4" | 2004
| 10.5 × 12.8 in (266.70 × 325.12&nbsp;mm)
| 7
|-
| microBTX
| 10.5 × 10.4 in (266.70 × 264.16&nbsp;mm)
| 4
|-
| nanoBTX
| 10.5 × 8.8 in (266.70 × 223.52&nbsp;mm)
| 2
|-
| picoBTX
| 10.5 × 8.0 in (266.70 × 203.20&nbsp;mm)
| 1
|}

The heat sink to be attached to the CPU, called "Thermal Module" throughout the official specification, is no longer attached solely to the motherboard, but to the casing itself, so that the inertial load of its mass during a mechanical shock event can no longer damage the motherboard.

The structural interface between the heat sink and the chassis, is defined as 4 mounting holes with the distances of 4.4 × 2.275 in (55.79 × 111.76&nbsp;mm) between one another. And since this attachment means is also required to have a certain stiffness, it is called "Support and Retention Module (SRM)" in the specification.

==Reception==

The BTX form factor has not been widely adopted despite its improvements over [[ATX]] and related standards. As a result, the availability and variety of BTX-compatible components is limited.

One reason for the failure of BTX to gain traction in key markets was the rise of energy-efficient components (CPUs, chipsets and GPUs) which require less power and produce less [[waste heat]], eliminating two of the primary intended benefits of BTX. Another reason was the lack of OEM adopters.<ref name="techwarelabs.com">{{Cite web|url=http://www.techwarelabs.com/articles/other/btx/|title=Techware Labs - Articles - BTX vs ATX: Is BTX Doomed?|website=www.techwarelabs.com}}</ref>

Initially, only Gateway and Dell offered computers with the new format, later HP and Fujitsu-Siemens (now Fujitsu) also offered some BTX-based computers. Most other manufacturers stayed with the ATX standard, and even the handful of manufacturers who did adopt BTX for some products continued to produce the bulk of their machines with the ATX form factor.

==References==
{{Reflist|30em}}

==External links==
* [http://www.anandtech.com/showdoc.aspx?i=1876 Balanced Technology eXtended (BTX) Form Factor — The Future of Cases & Motherboards] from [[AnandTech]]
* [http://www.hardwareanalysis.com/content/article/1773/ Hardware Analysis' evaluation of the BTX proposal] {{Webarchive|url=https://web.archive.org/web/20101231003703/http://www.hardwareanalysis.com/content/article/1773/ |date=2010-12-31 }}
* [http://www.anandtech.com/printarticle.aspx?i=2070 Anandtech's coverage] of a 2004 trade show, where Intel featured BTX.
* [https://web.archive.org/web/20160307062248/http://tech.gamecentralnetwork.net/?id=1811 "Whatever happened to BTX?"] by Jon Chappell at Game Central Network
* [http://mini-itx.com/16444708 Intel to offer Mini-ITX desktop board]
* [http://www.intel.com/products/desktop/motherboard/ Intel Desktop Boards Products List]
* [https://web.archive.org/web/20160305072711/http://www.theinquirer.net/inquirer/news/1038585/intel-btx-chassis-designs-cause-fury-from-partners Intel BTX chassis designs cause fury from partners]
* [https://web.archive.org/web/20191226221547/https://www.theinquirer.net/inquirer/news/1030561/intel-persuades-hardware-makers-to-shift-to-one-kilo-btx-heatsinks Intel "persuades" hardware makers to shift to one kilo BTX heatsinks]
* [http://www.evercase.co.uk/BTXTechnology.htm BTX information and products]

===Documentation===
* [http://www.formfactors.org FormFactors.org], an Intel-sponsored website dedicated to maintaining data and tools regarding the implementation of various form factors.
** [http://www.formfactors.org/developer/specs/BTX%20Chassis%20DG%201_1.pdf Balanced Technology Extended (BTX) Chassis Design Guidelines] Revision 1.1
** [http://www.formfactors.org/developer/specs/BTX_Specification%20v1.0b.pdf Balanced Technology Extended (BTX) Interface Specification] Revision 1.0b
** [http://www.formfactors.org/developer/specs/BTX_v1.0_errata_A.pdf Balanced Technology Extended (BTX) Interface Specification Errata A] Revision 1.0
** [http://www.formfactors.org/developer/specs/BTX%20System%20Design%20Guide_1.1.pdf Balanced Technology Extended (BTX) System Design Guide] Revision 1.1
** [http://www.formfactors.org/developer%5Cspecs%5CSDG%20EPC%20Case%20Study%20v.1.0.pdf Balanced Technology Extended (BTX) Entertainment PC Case Study] Revision 1.0
{{Computer form factors}}

{{DEFAULTSORT:Btx}}
[[Category:IBM PC compatibles]]
[[Category:Motherboard form factors]]