Choose Your Form Factor

The Birth of Mini-ITX

Mini-ITX was originally launched by VIA as a reference design to showcase its core products—chipsets and processors. The enthusiastic consumer response to these boards spurred VIA to begin commercial production. The VIA EPIA line of Mini-ITX mainboards was formally launched in 2002¹. Logic Supply began offering this new form factor and related components shortly afterward.

The appeal of the boards derived, in large part, from their usability. Mini-ITX boards offer all the features of a standard PC mainboard, but in a much smaller, energy-efficient package while still being x86 compatible. The form factor measures 17 x 17 cm (6.7" x 6.7") and frequently contains an integrated processor. The EPIA line was especially popular among computer hobbyists eager for a smaller alternative to their large desktop towers. VIA's marketing took note, and to this day the company focuses on consumer products utilizing the EPIA line of mainboards.

This combination—PC similarity and consumer attractiveness—is perhaps why hard core embedded designers have in the past looked suspiciously at Mini-ITX. But now we are seeing the form factor frequently used in more traditional "embedded" areas. Industrial board manufacturers like MSI, Jetway, IEI, and Quanmax have taken notice and are now offering a broad range of Mini-ITX solutions, the newest ones capable of carrying Ultra Low Voltage Celeron M, Core 2 Duo Mobile, and the new Intel Atom line of processors.

In 2003, VIA first proposed the Nano-ITX form factor and in 2005, formally released it into the market². Then, in May 2007, VIA introduced the exciting, super small Pico-ITX mainboard³. The PX-series has experienced much success, and after a little delay and hesitancy by case manufacturers, we have now seen a broad range of enclosures designed specifically for the Pico-ITX form factor.

The latest Intel-based mainboard additions offer both technical and business advantages, and this lean toward the development of more high-performance, industrial boards is being fueled by the market's demand.

A Form Factor For Every Occasion

Mini-ITX, Nano-ITX, and the new Pico-ITX mainboards are defined by their size, layout, and degree of integration and compatibility. Each form factor offers distinct qualities and should be utilized accordingly in order to effectively benefit from each one's output and size.

Sizing Down

As each form factor becomes progressively smaller, new advantages begin to surface. At 17 x 17 cm, the Mini-ITX mainboard is hardly the smallest of the standard embedded SBCs. It is, however, significantly more compact than a traditional ATX PC board and suitable for many applications where smaller, but not micro, sizing is desired. The Nano-ITX checks in at 12 x 12 cm, making it highly useful for embedded applications that don't allow for much wiggle room. These boards typically offer very little or no back panel I/O, but include all the necessary onboard connectors for just about any output requirement. Now enters the Pico-ITX, sizing down to a mere 10 x 7.2 cm. Although it is still fairly new to the market, this board proves to be more affordable and better designed when compared to its earlier Nano-ITX predecessors. The PX10000G "is designed to enable system developers and OEMs to create smaller, lighter, quieter and even more mobile devices than ever before"⁴ due to its very compact, very versatile platform.

Fitting In

In contrast to smaller form factors, the extra real estate on the Mini-ITX board creates ample space for integrated I/O. The layout of the mounting holes, back panel I/O shield, and PCI slot is similar to ATX-style PC boards. In fact, this standardized layout encouraged the rapid development of Mini-ITX specific chassis. Moreover, most Mini-ITX mainboards work with standard ATX power supplies and a 20-pin ATX power connector. Being backward compatible⁵, a Mini-ITX board can even be used in an ATX enclosure. Few cases have been designed for Nano-ITX mainboards, due to the lack of back panel I/O and need for additional cables to output from the onboard connectors. However, this drawback does allow for ease of use in custom enclosures and accessibility to LVDS for POS or kiosk applications. The new Pico-ITX mainboard now has a wide range of chassis available⁶, such as Serener's GS-L08 and Casetronic's TE-D288, the first Pico-ITX enclosure to be outfitted with an optical drive bay.

Processing Power

Mini-ITX mainboards have a wide variety of processors available in a broad range of packages, FSB speeds, and power output. While most VIA boards have integrated processors—VIA Eden, C3, C7, and now the new Nano—there was one VIA-manufactured board, VB6002G, that used Intel's Pentium M processor. The lure of VIA's processors is that they are power-efficient, lower cost, and fully x86 compatible. Also, many of VIA's mainboards are available in fanless versions, which can allow for solid state configurations. VIA's processors are ideal for embedded applications where versatility, efficiency, and stability are key. For applications requiring more brute processing power, Intel-based mainboards are available.

The latest Core 2 Duo Mobile and Atom families of processors have opened up new possibilities for the Mini-ITX form factor. The earlier Intel-based Mini-ITX boards were equipped with Pentium 4 processors—these were powerhouses, consuming watts and generating more heat than most Mini-ITX cases could handle. This seems counter-intuitive to the foundation of Mini-ITX. However, with the introduction of Pentium M, Celeron M ULV, and Core 2 Duo Mobile and Atom processors, an alliance between high performance and power efficiency has formed. For more information of Intel's processors, see Logic Supply's FAQ.

AMD also provides some interesting opportunities in the realm of über energy-efficient processors. It promises the best performance-per-watt⁷ and has contributed to some highly efficient, industrial-grade, Mini-ITX mainboards.

Traditionally, the Nano-ITX and Pico-ITX mainboards were only offered through VIA and thus, are limited to VIA's line of integrated processors. But, Jetway has released a sample of its own Nano-ITX form factor, the J8F9 series. This one has an onboard AMD Geode LX800 processor. It also has back panel audio output, which hasn't been seen on a Nano-ITX board since VIA's first-released N-series.

Axiomtek also has released a Pico-ITX form factor mainboard sans VIA processor and chipset. The PICO820 features an Intel Atom Z500-series processor and US15W controller hub. This seems to be an excellent, energy-efficient solution for embedded systems; however, custom enclosures might be the only option for this board. Even though it matches the same back panel I/O layout as the VIA PX-series boards (LAN, VGA), it has a +5V power input, which would interfere with current Pico-ITX enclosures.

What About that I/O?

Just like a regular PC, Mini-ITX boards have a range of I/O ports available: serial, parallel, USB, FireWire, keyboard/mouse, PCMCIA, audio, VGA, TV & S-Video, 10/00 LAN, IDE and SATA slots usually come standard. The newer boards feature onboard CompactFlash, DVI, HDMI, dual LVDS, YPbPr, Gigabit LAN, SATA (3 Gb/sec.), and programmable Digital I/O ports. As mentioned above, the Nano-ITX and Pico-ITX boards have this output available, but it must be accessed via onboard pin headers.

All Mini-ITX mainboards come with a PCI or PCI Express slot, and some also include Mini PCI and the newer PCIe Mini Card (Intel platform specific), enabling additional add-on modules like video capture cards and extra network or wireless interfaces. With the use of dual PCI riser cards, it’s possible to add up to two PCI cards and increase your platform's expandability.

The older mainboards used standard DDR266 or DDR400 memory but the latest additions are now equipped with the faster DDR2 533, DDR2 667, and DDR2 800 memory. Some use the laptop-style SO-DIMM memory, which is becoming more common as we see some of the new Intel Montevina-based platforms emerge.

Power Management with Ease

The high-end Mini-ITX boards offer a watchdog timer and standard system monitoring interfaces, not unlike many embedded computer boards such as VME. Most mainboards come standard with various other system management tools such as: Wake on LAN, Wake on Ring, Wake on Keyboard, CPU temperature monitoring, CPU voltage monitoring, fan control, and power management. These items are controlled and set in the BIOS.

The latest VIA EPIA series mainboards offers the VIA Padlock Security Suite. This consists of an on-die hardware number generator and Advanced Cryptography Engine. The hardware number generator harvests oscillations across the die for an extremely high degree of randomness. This can be used for the creation of Virtual Private Networks and Digital Certificates. The integrated cryptography engine offers on-the-fly data encryption and decryption and encoding of locally stored data. The VIA Padlock Security Suite offers almost transparent encryption, with minimal impact on system performance.