Mini-ITX

A VIA EPIA-M910 mini-ITX motherboard

Mini-ITX is a 17 × 17 cm (6.7 × 6.7 in) low-power motherboard, developed by VIA Technologies in 2001.^[1] They are commonly used in small-configured computer systems. Originally, they were a niche product, 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. The four mounting holes in a Mini-ITX board line up with four of the holes in ATX-specification motherboards, and the locations of the backplate and expansion slot are the same^[2] (though one of the holes used was optional in earlier versions of the ATX spec). Mini-ITX boards can therefore often be used in cases designed for ATX, micro-ATX and other ATX variants if desired.

The design has provision for one expansion slot. Earlier motherboards conventionally have a standard 33 MHz 5V 32-bit PCI slot. Many older case designs use riser cards and some even have two-slot riser cards, although the two-slot riser cards are not compatible with all boards. Some boards based around non-x86 processors have a 3.3V PCI slot, and the Mini-ITX 2.0^[3] (2008) boards have a PCI-Express ×16 slot; these boards are not compatible with the standard PCI riser cards supplied with older ITX cases.

History

ITX motherboard form factor comparison

In March 2001, the chipset manufacturer VIA Technologies released a reference design for an ITX motherboard, to promote the low power C3 processor they had bought from Centaur Technology, in combination with their chipsets. Designed by Robert Kuo, VIA's chief R&D expert, the 215×191 mm VT6009 ITX Reference Board was demonstrated in "Information PC" and set-top box configurations. He would later go on to design the Mini-ITX design. At that point, the ITX design was taken up by few manufacturers, but Shuttle, Jetway, etc. produced many ITX based cube computers. Other manufactures instead produced smaller boards based on the very similar 229×191 mm FlexATX configuration.

In October 2001, VIA announced their decision to create a new motherboard division, to provide standardized infrastructure for lower-cost PC iterations, and focus on embedded devices. The result was the November 2001 release of the VT6010 Mini-ITX reference design, once again touted as an "Information PC", or low cost entry level x86 computing platform. Manufacturers were still reticent, but customer response was much more receptive, so VIA decided to manufacture and sell the boards themselves. In April 2002 the first Mini-ITX motherboards—VIA's EPIA 5000 (fanless 533 MHz Eden processor) and EPIA 800 (800 MHz C3)—were sold to industrial customers.

Enthusiasts soon noticed the advantages of small size, low noise and power consumption, and started to push the boundaries of case modding into something else—building computers into nearly every object imaginable, and sometimes even creating new cases altogether. Hollowed out vintage computers, humidors, toys, electronics, musical instruments, and even a 1960s-era toaster have become homes to relatively quiet, or even silent Mini-ITX systems, capable of many of the tasks of a modern desktop PC.

Mini-ITX boards primarily appeal to the industrial and embedded PC markets, with the majority sold as bulk components or integrated into a finished system for single-purpose computing applications. They are produced with a much longer sales life-cycle than consumer boards (some of the original EPIAs are still available), a quality that industrial users typically require. Manufacturers can prototype using standard cases and power supplies, then build their own enclosures if volumes get high enough. Typical applications include playing music in supermarkets, powering self-service kiosks, and driving content on digital displays.

VIA has continued to expand its Mini-ITX motherboard line. Some of the earlier generations included the original PL133 chipset boards (dubbed the "Classic" boards), CLE266 chipset boards (adding MPEG-2 acceleration), and CN400 boards (which added MPEG-4 acceleration). Second generation boards featured the EPIA M, MII, CL, PD, TC and MS — all tailored to slightly different markets. Legacy VIA boards use their x86-compatible CPUs — the C3, C7 or low-power Eden variants, with newer boards featuring the VIA Nano CPU, launched in May 2008.^[4] Other manufacturers have also produced boards designed around the same layout, using VIA, but also Intel, AMD, Transmeta and PowerPC technology.

Intel has introduced a line of Mini-ITX boards for the Atom CPU, which demonstrates a significant increase in processing performance (but without added power consumption) over older VIA C3 and C7 offerings and is key to making the design viable for use in personal computers. Other manufacturers saw the potential of the design, and followed suit, some even not limiting themselves to the Atom, as evidenced by Zotac GeForce 9300-ITX board^[5] that supports Core 2 Duo CPUs with FSB frequencies up to 1333 MHz, two separate-channeled 800 MHz memory slots and fully functional PCI Express 2.0 x16 slot that could connect through SLI to the onboard video.^[6] This new wave of offerings has caused Mini-ITX to explode in popularity among home users, hobbyists and even overclockers.

Intel is currently one of very few manufacturers of Mini-ITX mainboards that also include the mechanical dimensions in their manuals.^[7]

Intel-based products

Onboard CPU

Intel D945GCLF2D Atom 330 Mini-ITX motherboard

A number of manufacturers have released Intel Mini-ITX motherboards that feature onboard CPUs, often mobile or low-TDP versions. These Intel processors are designed to draw minimal power resulting in lower TDP ideal for fanless (passively cooled) configurations and embedded applications.^[8][9][10]

Socketed CPU

Zotac NF630I-D-E LGA 775 Mini-ITX motherboard

Starting from LGA 775, socketed Intel Mini-ITX motherboards have been released by Intel^[11] and Zotac.^[12][13][14] This was followed by LGA 1156 motherboards^[15][16][17] Starting from LGA 1155, Mini-ITX motherboards have started to become mainstream, with many different manufacturers releasing products. This is partly because almost all Sandy Bridge and Ivy Bridge Intel Celeron, Pentium and Core series CPUs have integrated processor graphics, eliminating the need for motherboard graphics or discrete graphics cards.^{[18][19][20][21]} This trend has continued with LGA 1150 CPUs.^{[22][23][24][25]}

Due to the limitations of the Mini-ITX design, and the physical size of the LGA 2011 socket, Mini-ITX motherboards with the socket only support dual-channel memory (two DIMM slots) and a single PCI Express expansion slot, and they require using the narrow-ILM version of the LGA 2011 socket. Despite this, manufacturers have released LGA 2011 based Mini-ITX motherboards.^[26]

AMD-based products

A number of manufacturers have released several socketed AMD Mini-ITX motherboards, supporting Socket AM2,^[27] Socket AM2+,^[28] Socket AM3,^[29] Socket FM1,^[30][31] Socket FM2,^{[32][33][34][35]} Socket FM2+,^[36][37][38] and Socket AM1^{[39][40][41][42]} CPUs. Socket AM2+ and AM3 ITX motherboards have integrated motherboard graphics, while discrete graphics or processor integrated graphics are required for other platforms.

Mini-ITX motherboards with integrated AMD CPUs are also released.^{[43][44][45][46][47][48][49][50]} These motherboards often use mobile CPUs and feature passive cooling, and feature more powerful integrated graphics compared to their Intel counterparts, which makes them suitable for HTPC uses.

Transmeta-based products

IBASE made the first Transmeta-based Mini-ITX motherboard, the MB860. The board makes use of Transmeta™ Efficeon™ processors running up to 1.2 GHz. It supports SO-DIMM DDR modules with capacities up to 1GB. The onboard 16MB ATI M7 graphics controller delivers compelling performance in 3D games and graphical intensive programs. It has four USB 2.0 ports, a Realtek 8100C 10/100 BaseT Ethernet and an optional 8110S Gigabit Ethernet controller.

PowerPC-based products

The first PowerPC motherboards were produced by Eyetech^[51] in 2005^[52] but they stopped any activity in 2005.^[53] So company ACube Systems made a new board, the Sam440ep,^[54] primarily for the AmigaOS market.

Power

Mini-ITX 2.0 SoC mainboard with ATX12V connector installed in a Micro-ATX computer case.

The Mini-ITX standard does not define a standard for the computer power supply, though it makes some suggestions of possible options. Conventionally Mini-ITX boards use a 20- or 24-pin "original ATX" power connector. This is usually connected to a DC-DC converter board which in turn is connected to an external power adapter. Generally both the power adapter and the DC-DC board are supplied with the case.

Some boards have built in DC-DC converters and converters have also been made to plug directly into the ATX connector (e.g. the PicoPSU), either of these options avoids the need to mount a separate DC-DC converter into the case, saving space and design effort. Boards using full-power Intel or AMD CPUs typically use ATX12V 2.x connections and require a case with appropriate power supply and cooling for these more power-hungry chips. Defined by the ATX specification, power supplies with ATX12V connector on a separate 12 volts rail must not idle that 12 volts rail.

See also

Wikimedia Commons has media related to Mini-ITX.

• EPIA, Mini-ITX, Nano-ITX and Pico-ITX motherboards from VIA
• Home Theater PC
• Mini ATX, 15 × 15 cm (5.9 × 5.9 in) form factor developed by AOpen
• Mobile-ITX
• Nano-ITX
• Pico-ITX
• Plug computer

References

External links

• VIA Website - VIA Spearhead Initiative - Mini-ITX Mainboard Design
• Logic Supply - Mini-ITX Advantages