BTX

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BTX case

BTX (for Balanced Technology Extended) is a form factor for motherboards, originally slated to be the replacement for the aging ATX motherboard form factor in late 2004 and early 2005. It has been 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. Intel's decision to refocus on low-power CPUs, after suffering scaling and thermal issues with the Pentium 4, has added some doubt to the future of the form factor. The first company to implement BTX was Gateway Inc, followed by Dell and MPC. Apple's Mac Pro utilizes the elements of the BTX design system as well but is not BTX compliant. However, future development of BTX retail products by Intel was canceled in September 2006. A proprietary form factor is now used by many companies.^[1]

Enhancements

• Low-profile - With the push for ever-smaller systems, a redesigned backplane that shaves inches off height requirements is a benefit to system integrators and enterprises who use rack mounts or blade servers.
• Thermal design - The BTX layout establishes a straighter path of airflow with fewer obstacles, resulting in better overall cooling capabilities. A 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 - The BTX standard specifies different locations for hardware mounting points, thereby reducing latency between devices^{[citation needed]} 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 and Southbridge chips are located near each other and to the hardware they control.

Pico BTX

BTX form factor motherboard inside a Dell Dimension E520.

Pico BTX is a motherboard form factor that is meant to miniaturize the BTX standard. Pico BTX motherboards are relatively small, 10.5"x8" (smaller than many current 'micro'-sized motherboards), hence the name 'pico'. These motherboards share a common top half with the other sizes in the BTX line, but sport only one or two expansion slots, designed for half-height or riser-card applications.^[2]

Compatibility with ATX products

The BTX form factor motherboards are incompatible with most of the ATX form factor cases and vice-versa. Moreover, cases such as the Cooler Master Series (Stackers) support a varying range of motherboard types such as ATX, BTX, Mini-ATX and so forth. However, all connectors are compatible, including power supplies, PCI cards, processors, RAM, hard drives, etc.

Criticism

BTX's thermal design specifies a particular processor location at the front of the board, where a special case ventilation duct is located. It places the northbridge behind the processor, and memory DIMMs beside the northbridge, arranged parallel to front-to-back airflow. Unfortunately, this is not possible for processors with an integrated memory controller (on-die northbridge), such as the Athlon 64 and Intel Core i7.^[3] To equalize the length of the signal traces to the DIMMs, these processors must be centered in front of them. The DIMMs cannot go beside the processor, because they would then extend past the front of the motherboard, and they would obstruct the airflow if positioned behind it.

The BTX form factor has still not been widely adopted despite the age of the extremely common ATX and related standards. As a result, the selection of key BTX parts may be limited or unavailable. The exceptions are select OEMs who are generally able to supply ample replacement parts for such systems albeit at a less competitive cost. Large customers are usually able to secure favorable support contracts which negate such disadvantages but small businesses and home users may find third party support for such systems more expensive, raising the cost of ownership.

The market for ATX boards and power supplies is still extremely large and competitive with little signs of changing in the near future. There are few advantages seen to BTX and many issues which hamper adoption. Those who are invested in ATX have the option of using cases and power supplies between platform generations, as well as a wide array of OEM and third party support options. The ATX platform generally offers a much wider range of processor and chipset options than the mostly Intel BTX platform. To date, AMD has offered few BTX product options and has emerged as major and viable player in the computer industry.

The hobbyist and gaming markets are major consumers of highly-profitable, high-end hardware and they demand a large selection of standardized components and parts from a large variety of manufacturers, which BTX has yet to offer. In addition, they tend to be early adopters of technology products and exert a large influence over industry trends and the eventual mainstream. BTX would likely need to penetrate this market before large scale adoption will occur.

Currently there is a trend toward energy efficient hardware and cooler designs which produce less heat, making BTX less advantageous. Intel has also made major shifts in response to heightened competition in recent years and has released smaller and cooler running processors than what may have been anticipated.

See also

• List of computer standards

References

1. ^ BTX development cancelled
2. ^ http://www.tomshardware.com/reviews/beginners-guide-motherboard-selection,1289-5.html
3. ^ Dan's Data criticises the BTX standard

External links

• Balanced Technology eXtended (BTX) Form Factor — The Future of Cases & Motherboards from AnandTech
• Hardware Analysis' evaluation of the BTX proposal
• Anandtech's coverage of a 2004 trade show, where Intel featured BTX.
• "Whatever happened to BTX?"
• Intel to offer Mini-ITX desktop board
• Intel Desktop Boards Products List

Documentation

• BTXFormFactor.com, BTX Form Factor Information
• FormFactors.org, an Intel-sponsored website dedicated to maintaining data and tools regarding the implementation of various form factors.
  • Balanced Technology Extended (BTX) Chassis Design Guidelines Revision 1.1
  • Balanced Technology Extended (BTX) Interface Specification Revision 1.0b
  • Balanced Technology Extended (BTX) Interface Specification Errata A Revision 1.0
  • Balanced Technology Extended (BTX) System Design Guide Revision 1.1
  • Balanced Technology Extended (BTX) Entertainment PC Case Study Revision 1.0