Hordes of VIA acolytes have been making very small computers out of very small mini-ITX motherboards for several years now.

The trouble is, while mini-ITX boards are small and contain a pre-fitted CPU and graphics chipset, they’re larger than the latest breed of desktop imps spearheaded by the Mac mini. VIA’s response is the nano-ITX motherboard. Where mini-ITX was very small at 170 x 170mm, nano-ITX is tiny, measuring just 120mm x 120mm.

The board forms almost a complete PC by itself, requiring only a SODIMM memory module and storage. At its heart is the VIA Luke CoreFusion; this is a single component package integrating an Eden N processor running at 533MHz, S3 UniChrome Pro AGP graphics and a CN400 north bridge. The only other major chip on the board is the south bridge, which accommodates 10/100 Ethernet, a USB 2 controller, two parallel ATA channels and a single SATA interface.

The backplane sports a small but useful array of standard-sized connectors, with two USB ports, RJ-45 Ethernet socket, VGA output and analogue audio connectors, plus one PS/2 port. There’s also a single RCA phono socket that can be configured either as a TV or S/PDIF audio output. There are header connectors for four more USB ports, plus an LVDS/DVI output header. You’ll find a mini-PCI socket on the underside too.

With the close physical proximity of the CoreFusion package and the south bridge, the 5000E has just one long heatsink to cover them both. With its 533MHz CPU core it runs cool enough to run without a fan: this is a totally passive board. Two faster variants exist: the 8000E, which runs passively at 800MHz, and the 10000E, which ups the ante to 1GHz but requires a small fan.
The 5000E is supplied with its heatsink uninstalled, since the single SODIMM memory module sits beneath it when it’s fitted. The system will take DDR400 memory, although slower types down to DDR266 will work too.

While the board is tiny, hooking it up to a power source and connecting video and Ethernet cables can make things unwieldy. Power is particularly messy: the standard ATX power connector is too large for the nano-ITX format, so there’s a far smaller proprietary 12-pin connector on the board itself that has to be connected via a clumsy adaptor.

Finding a case for it is another hurdle. Nano-ITX has had a long gestation period – over three years – but late last year the design specifications were changed. Therefore, most cases nominally designed for nano-ITX won’t accommodate the board; manufacturers have retooled for the revised specification but, to our knowledge, none of these designs are yet available. This is less of a problem than it would be for a standard system, since the external power supply (which you’ll need to buy separately) means that all you need is a square box with some holes drilled in the right places to physically hold the board, and a mount for an optical or hard drive.

The Eden processor is fully x86-compatible, so you can install and run Windows with no problem; the drawback is its relatively limited computing power. We installed Windows XP with no problems: it just took a long time. A bare installation is acceptably snappy when it comes to merely navigating around XP itself, but modern applications simply don’t expect to find themselves running on a 533MHz processor with only 64KB Level 2 cache.

So we also tried a different approach. We made an entirely passive system, booting Linux from a USB flash drive. The current BIOS in the board doesn’t support the USB-HDD boot-up option that makes for the most painless USB boot, but we had success with DSL (Damn Small Linux - www.damnsmall linux.org), which includes a routine for configuring a flash drive as a bootable USB-ZIP device. The result was a fully functional but lightweight OS with full GUI, and it ran fast enough to use day-to-day, in complete silence.

With the board on the bench in free air, the heatsink did get warmer than expected. However, measuring power consumption in the Labs confirmed that the 5000E is very frugal compared to any standard desktop board. With the system booted into DSL but idle, power consumption averaged a mere 10.5W, rising to only 14W or so when the CPU was heavily loaded. This is about one-twentieth of the power consumption of a modern standard desktop system.

Whatever the drawbacks, there’s no way you can’t love a fully x86-compatible board that’s so tiny. VIA has never claimed nano-ITX boards are consumer-grade devices; the company is more interested in pitching it to embedded-design manufacturers. But if you’re the type of enthusiast who enjoys some technical obstacles, you’ll have a lot of fun with the 5000E and its variants. Just don’t expect to run Windows XP as if it were a standard system.