Thin Mini-ITX: The perfect small form factor PC?

Towards the end of 2012 I built a SFF (Small Form Factor) PC for one of the kids. The key requirement for the PC was that it should occupy the minimum of space yet it needed to offer all the features of a modern PC, including a decent processor, a fair-sized screen and a proper mouse and keyboard.

I plumped for a Mini-ITX form factor and once I had delved into my Pile Of Parts I ended up with an Intel DH67CF motherboard, 3.1GHz Core i3-2100 dual core CPU, 8GB Crucial DDR3 RAM and a Corsair Neutron SSD.

The key part of the build was an Akasa Crypto VESA chassis, which hangs on the VESA mounts at the rear of a TFT display. I have built Mini-ITX PCs before but this was my first time going down the VESA route so I carefully selected a Dell IN2030M display which costs a mere £80 new. The Dell screen measures 20in on the diagonal with a 1,600 x 900 resolution, so it’s good for 720p HD but cannot display Full HD.

This was a deliberate choice on my part as I wanted to give the feeble Intel HD Graphics 2000 an easier ride and also wanted to ease the burden on the Wi-Fi connection between the PC and the home router as our kids use YouTube as a jukebox. HD Flash hammers a lightweight processor and demands plenty of Internet access for relatively little reward.

I ran into two minor problems during the build. The first was that the stock Intel cooler took up most of the room inside the Akasa chassis so I had nowhere to mount the 2.5in Corsair SSD.

Forget about a slimline optical drive, I was struggling to install the SSD. The point here is that Mini-ITX is typically skewed towards tiddly processors such as Intel Atom that can survive with a tiny passive cooler to keep their 10W TDP under control, whereas I was dealing with a 65W Core i3-2100. My solution was to mount the SSD on the top cover of the case using the ventilation holes for the fixing screws.

/With the PC built I plugged in a USB DVD drive, installed 64-bit Windows 7 along with Microsoft Office and a host of driver updates and then I ran into my second problem, and this one was completely unexpected. I chose the Dell display as it has a basic stand that only allows tilt adjustment (i.e. no pivot or height adjustment) and was confident the Akasa chassis would simply hang on the four VESA screws, however I was wrong. Dell has covered the tilting hinge with a plastic shroud to hide the metalwork from sight and this gets in the way and prevents the PC from sitting in place. My answer was to remove the plastic using a hacksaw until I had sufficient clearance.

The finished PC works well and does pretty much exactly what I hoped, although the Intel graphics are rather feeble and can only play Minecraft with the quality settings turned down to the minimum. At idle the PC draws 25W at the mains plug, which rises to 45W under load, but it is very quiet and unobtrusive.

Overall I give myself eight marks out of ten for this PC build however I doubt I would make the same set of decisions again. One possible avenue would be a switch from Intel hardware to the AMD FM2 platform to unlock more graphics grunt, although that might require a bit of thought as the AMD A10-5700 quad core with integrated HD 7660D graphics draws about 110W under load. That is trivial in a mid-tower case but something of a challenge with a Mini-ITX chassis.

The alternative is to stick with Intel hardware and make the PC even smaller and more compact. This approach is made possible by the Thin Mini-ITX form factor that first made an appearance at Computex 2011 and is a low profile version of Mini-ITX with a Z dimension (height) of 20mm.

A quick trawl through Wikipedia throws up a massive list of 30 motherboard form factors that range from the huge WTX (356 x 425mm) to the tiny CoreExpress (58 x 65mm). If we concentrate on the more recognisable standards we are left with EATX (305 x 330mm), ATX, microATX, Mini-ITX and Pico-ITX (100 x 72mm) but it is worth noting that these figures refer to the area of the motherboard and make no mention of the height of the components. In the case of a tower PC the height of the motherboard components and the processor cooler affect the width of the chassis as the motherboard is mounted on one side of the case.

This can have some curious consequences. If we take two extreme examples in the form of the Mini-box M350 from the Mini-ITX Store and the Cubitek Mini Ice, which are both classed as Mini ITX cases, yet they could hardly be more different from each other.

The Cubitek can accommodate a full sized gaming graphics card and uses a regular ATX power supply while the M350 restricts you to integrated graphics and forces you to spend some cash on a power adapter and DC-DC power converter.

Despite these differences the two cases present a regular 40mm high I/O shield to the outside world however Thin Mini-ITX reduces this dimension to 20mm.

That might not sound like a radical change but it has several key consequences, starting with the obvious need to cut down the number of ports and connectors on the I/O panel. There simply isn't room to supply a full array of audio jacks, eight USB ports and three graphics connectors so you can expect a handful of USB 3.0 ports, an Ethernet connector and digital graphics outputs such as HDMI and DisplayPort.

Elsewhere on the motherboard you will likely find that the memory slots support laptop SODIMM memory rather than desktop RAM to reduce the height of the components.

The other half of the equation is the case or chassis as this needs to have the correct opening for the I/O shield, which brings us to two new cases from Akasa.

The Cypher is a conventional slender case that is smaller than the Crypto however our focus here is the Euler, which is a chunky piece of engineering that uses passive cooling to keep the Intel processor under control. This brings us neatly to the subject of cooling, which is an important consideration during a Mini-ITX build and which results in many Small Form Factor PCs being restricted to a weedy processor with a low TDP.

Intel has released three Thin Mini-ITX motherboards to showcase the new form factor and the first of these is the DN2800MT, which has a soldered Atom processor with a power draw around 10W.

More usefully Intel has also released models called DH61AG and DQ77KB that support LGA1155 processors with a maximum TDP of 65W although the form factor is best suited to a TDP of 35W.

Intel sent a DQ77KB motherboard with a Core i3-3220T, which is a dual core processor that runs at 2.8GHz with a maximum TDP of 35W. Intel also sent us its HTS 1155LP cooler, which looks like an oversize laptop cooling system that would have a natural home inside a blade server. This active cooler was put to one side as the Akasa Euler case doesn't require any extra cooling and the Intel hardware wouldn't have fitted anyway.

The other hardware we used in the build was a 16GB (2x8GB) Crucial CT2KIT102464BF160B DDR3-1600MHz kit that costs £66 and a 120GB Corsair Force 3 SSD that weighs in at £85.

Assembling the PC is a novel process, but that is entirely thanks to the passive nature of the Akasa Euler case. The motherboard, processor and memory go together in the usual way and the 20mm I/O shield pops into the case just as you would expect. Intel includes a standard 40mm I/O shield in the package so you could use the DQ77KB in a regular PC case if you choose.

Where things get a touch weird is that the assembled motherboard drops into the case upside down, such that the processor heat spreader makes contact with the machined inner surface of the case. Once the motherboard is screwed down the heat passes directly from the processor to the body of the case and is dissipated into the surrounding air.

As we were using an SSD rather than a hard drive there were no moving parts in the PC and it was completely silent in operation.

This threw up a curiosity as my usual practice is to disconnect the front panel activity lights as I really don't need to know that the hard drive, for instance, is working as I can figure that out for myself thanks. The Euler case has an intense blue power LED but when the light was disconnected it wasn't immediately apparent that I had pressed the power button as the PC takes a few seconds to display the POST screen. In those few seconds there were absolutely no signs of life as the PC is, as mentioned, silent.

My other concern was the choice of HDMI and DisplayPort graphics outputs on the DQ77KB as few displays have a DisplayPort connector and Windows graphics drivers don't seem to work very well with HDMI. The problem is one of over scanning where the image is larger than the screen and while this works fine with a movie on your TV it is a real pain for a PC Operating System on a desktop screen. Thankfully Intel includes an HDMI-to-DVI adapter in the motherboard package so there are plenty of options for the customer.

The finished article is a triumph. It looks good, is very small and utterly silent and has stacks of processing grunt. The weakest point are the integrated Intel HD graphics 2500, which have a mere six execution units and mean you will struggle to play games such as Minecraft.. The obvious answer is an upgrade to a Core i3-3225 processor, which has Intel HD Graphics 4000 that employ 16 execution units. This processor has a higher TDP of 55W but that shouldn't pose any problems.

Our finished Core i3 PC drew 15W-20W at idle and had a maximum power draw of 30W under load. We can only hope that AMD will join in the Thin Mini-ITX fun but that might be wishful thinking.