Whether or not we're really in a 'post-PC' era is up for debate, but these are clearly changing times for the way we buy and use computers.
Mobile device usage may well be up, but even in these days of clouds, mobile phones and tablets, according to market analysts IDC the number of traditional PCs (desktop and laptops) sold every year is still growing, even in mature markets.
What is changing rapidly, however, is what those PCs look like. Thanks to ever less power hungry parts, thin and quiet Ultrabooks are on the up, while noisy, cheap and power hungry desktops are on the way down. It's a trend which favours small form factors and energy efficiency over the big old desktops of yore.
Which is why the new Xi3 from ISYS Technologies is an intriguing vision of the future. Shown off at CES earlier in the year, and recently at Design West, it's a small form factor desktop PC or server which - it's claimed - draws less than 20W when running flat out. By comparison, the average PC uses around 150W.
Even mini-ITX systems based on Via's C3 chip uses more energy, yet the Xi3 is built around an AMD Athlon 64 X2 processor. Not, perhaps, the most interesting of CPUs around or one you'd want to cut HD video on, but more than capable of running a Windows desktop and most associated applications.
And just as Ultrabooks and iPads take advantage of low power consumption to be creative and elegant with their design, so the Xi3 is a striking rethink of the way PCs are built. Measuring just over 10x9x9cm, it's capable of driving two 30inch monitors from a base unit that's around the size of a baked bean tin. Take that, Retina display.
In order to achieve this, ISYS has come up with its own, proprietary design for the internal components, which involves cutting the motherboard up into three distinct pieces. There's a board with the CPU on, one with the southbridge, and one for the rear ports too.
As a home PC, Xi3 is interesting, but all that clever architecture comes at too high a price. Starting at $849 it's impossible to justify over much more capable and versatile Acer S3 Ultrabook, for example, which only uses a bit more energy than the Xi3 but includes a screen. This isn't too much of a concern for ISYS as it has its eye on corporate sales and the data centre, where a few Watts saving per machine adds up to significant sums over five or six years.
To bolster its business case, a single Xi3 can be hooked up to three thin clients in order to provide virtual desktops for four employees.
These thin clients, called 'Zero Modules', cost less than $250 a pop and can take advantage of cheaper Windows licenses, but more importantly draw just 1W of power when on. So the argument put forward by ISYS is that you can have four desktops at a total power budget of just 24W. In a company with 2,000 employees, that's a potential saving of over 1,000kWh in a single seven hour working day.
Power efficiency on this kind of scale is a double win for corporates. Not only does it reduce running costs, it also helps them to meet environmental targets which are good for their image and help them meet guidelines for public sector contracts. However, the very inventiveness of the Xi3 may also be its undoing.
Xi3 price: too high - or better for other costs?
The biggest issue is still the price. There's a cost calculator on the website which shows the benefits over time for a corporate buyer, but there are some assumptions the company makes which seem unlikely. Firstly, that the Xi3 won't need replacing more often than a regular desktop, and secondly that all PCs are operational 24 hours a day.
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Adjust these two sliders and the high capital cost of each Xi3 almost completely counters the operational benefits. Furthermore, by default, it's assumed that a traditional desktop uses 200W of power - there's no reason why a cheap, new, modern corporate machine for email and cloud access should actually consume half of that.
On top of which, many corporates are encouraging employees to 'bring their own device' as a way of cutting costs and reducing power consumption, rather than refitting entire offices. Applications like Avaya's Aura Flare can put a fully functioning contact centre interface with telephony built in onto an Android tablet or iPad.
Green IT experts that TechRadar quizzed about Xi3 all agreed that the cost calculation isn't convincing enough for most companies, and that the expectation of being able to run four desktops from a single Athlon X2 seemed ambitious too. In addition, the fact that Xi3 is a closed and proprietary system from a young company makes it hard to buy into when an open platform is easier and better guaranteed to support in the long term.
Christine Headford is CIO of CO2High Ltd, a company that specialises in measuring firms' carbon footprint and helping to reduce it.
"The cost comparison goes in the Xi3's favour based on being able have four users, 24 hour operation (unlikely in an office environment) and that software licensing is cheaper on thin client," says Headford, "If you increase the spec to allow for four users, adjust to office hours and accept that software manufacturer will not be willing to reduce their income for thin client, the savings are much less convincing: down to less than 5% over 5 years."
It's early days for Xi3, though, and while it's not certain that this particular machine will take off yet, there's definitely room for an improved, cheaper version in the future. It's a reminder that next time your IT support team come round to repair or replace your desktop computer, they may not be quite living in a 'post-PC' era, but they do have options.