GLOBALLY, COMPUTERS USE A LOT OF ENERGY; and given the dominant role of fossil fuels in electricity generation, computing is therefore responsible for a lot of the increase in carbon dioxide in the atmosphere. The ‘carbon footprint’ of computing is thought to equal to that of aviation (about 3% of global energy use); some put its burden as higher, and it is clearly increasing fast.

Targeting data centres and the desktop

Attention falls in particular on the impact of data centres, where thousands of machines are racked up to store data, host Web pages, process transactions etc. The density at which these machines are co-located means that for every watt spent on computation and data access, another watt is spent extracting heat, so they are sinners twice over. There has also been a tendency at data centres to ensure operation 24/7 by running the machines full time regardless of the computational load, by over-provisioning, and by adding a layer of uninteruptable power supplies to the infrastructure.

In March this year, at the Royal Society conference on ubiquitous computing, I heard an interesting presentation by Professor Andy Hopper of the University of Cambridge, on the subject of Computing for the Future of the Planet. More recently, Andy reprised this topic as the inaugural lecture of the UKCRC. I recommend visiting Andy’s site where you can find his presentation slides, and the paper he has submitted to the Royal Society for publication.

I found myself in agreement with Andy’s ideas about locating data centres close to sources of renewable energy and ‘moving the bits’ rather than moving electrical power long distance and suffering transmission losses. I also applaud the work his team is doing on virtualisation, moving jobs around the data centre so as to shut down as much of the system as possible when it isn’t needed. But I confess I baulked at his urging that the personal workstation, the PC as we have come to know it in the last quarter century, should be abolished in favour of network-centric storage and services accessed from ‘thin client’ machines.

Defra purges the desktop

I recently attended a meeting of the Carbon Footprint Working Group set up by the British Computer Society. CFWG harnesses the energies and expresses the concerns of the BCS’s Ethics Forum, the Data Centres Specialist Group and the Communications Management Association. Of particular note is the work being done on a voluntary code of conduct for data centre operators, and a project part-funded by the Carbon Trust to develop software to help data centre management model the energy use of their systems and play ‘what-if’ experiments to find ways of being more energy efficient.

However, CFWG’s concern doesn’t end with data centres. At that meeting, we heard an interesting pair of linked presentation by Bob Crooks of the British government’s Department of Environment, Food and Rural Affairs (Defra), and by Richard Lanyon Hogg of IBM UK which provides Defra with extensive IT support.

IBM helped Defra conduct an audit of the energy cost of its ICT systems, using meters and thermal imaging cameras. The results showed inefficencies in many unexpected locations. A frequent culprit was departmental print servers. The survey has led to many reforms, including the abolition of many desktop systems and their replacement by laptops: Richard showed off the Lenovo ThinkPad which is now his sole machine for portable, home office, desktop and hot-desk use.

A plea for the peripheral

Laptops are great things. The need for them to run on battery power has been a great driver in the direction of energy efficiency. I wrote most of this blog text on an Apple PowerBook G4 laptop, on buses and in hospital waiting rooms. But I wonder — what kind of compromises does one accept by trying to use a laptop for everything? Energy efficiency is a good thing; so is human efficiency.

There are three kinds of work I do that are more efficiently accomplished by being done on my ‘desktop’ machine (actually, my Apple Macintosh G5, the largest computer I’ve ever had, is a tower system that lives in a trolley beside my desk, not on it).

  • Media publishing work in Adobe Photoshop, Illustrator and InDesign. It is a great benefit to have as much display space as possible, for two reasons — to see the document being worked on, in both extent and detail; also to have rapid access to the horde of control palettes. Otherwise one wastes much time calling up and dismissing palettes, and scrolling around the document surface: not very efficient!
  • Video editing work. Here the actual products being edited do not need so much display area, but two 720 x 576 video previews need to be accomodated size by side, and editing efficiency is enhanced by seeing a big horizontal slice of the ‘timeline’ at reasonable magnification. Plus, video editing can require the simultaneous use of many peripherals: in my case, at least one large and fast external drive, and a FireWire link either to my camcorder or my Sony DSR-20P digital VTR. Desktop machines can support more simultaneous connections to peripherals.

Now, arguably these publishing applications are one for which even Andy Hopper would make an exception. Editing video on a thin client system is certainly out of the question. But of course, these are specialisms which it would be rare to find in an office environment.

However, consider my third scenario, which can hardly be unusual among knowledge workers:

  • Working across many windows — It’s not uncommon for me to be writing a paper or a contribution to an online discussion (or this blog), composing text in one window while referring to several Web sites, PDFs and emails, each in their own window. I arrange the windows so I can tell enough by the bits poking out which contains what. At the moment I find I have 15 applications running, which isn’t unusual for me; and 8 open windows plus 7 minimised to the Dock — again, not unusual for me. This behaviour, which I find efficient in terms of research and writing productivity, is supported by the ‘affordances’ of a 1680 x 1050 pixel Apple Cinema Display.
NEC-8201a laptop

NEC-8201a laptop, circa 1983 – 32k of storage and a comms link to my Mac

But, hey! I have at times to remind myself that in 1986 I was working on the 512 x 342 pixel monochrome display of a Mac Plus. Many dialogue boxes in modern applications are bigger than that!

And what about my first laptop? The NEC PC-8201a (see right) had just six lines of forty-column type display. That required something like an orator’s sense of what point you had reached in the argument evolving just to the north of your fingers.

Ironically, you don’t get much more space when composing text for WordPress…

As we may think

One thing I felt about the Defra/IBM response to the challenge of controlling energy consumption by IT, as expressed in the CFWG meeting, was that their choices about ‘End User Devices’ were effectively limited by what technology is currently on the market. What if we allowed ourselves the luxury of imagining the EUD of the future? Would it look like a Lenovo laptop? Would it look like a PDA?

I hope it would be more modular than a laptop, for the sake of the environment. On my bookshelf, for I can’t bring myself to get rid of it, is a nice white Apple G3 iBook whose motherboard got fried a few months ago. To repair it would be expensive. Yet destined for the grave along with it is a perfectly good XVGA colour LCD display, CD-writer etc. Seems a waste. (I guess I could prise out the RAM chips and put the hard disk in an external drive box.)

I’d like the EUD of the future to be a small core device that can be extended like crazy to suit the task and environment at hand. Maybe it would be about the form factor of the Asus Eee PC (see Flash presentation), with small tolerable keyboard and trackpad, wireless networking and Ethernet, a daylight/backlit energy-saving screen somewhat like in the One Laptop Per Child XO machine, and about 16 Gb of flash memory. I envisage a clip-on base that provides bulk storage, mains power, a secondary battery or fuel cell and more expansion ports. For efficient desktop use, a better keyboard and mouse could be attached.

But for me, the real breakthrough would be how my envisaged device would work with external displays. Some models of Apple PowerBooks already show the way in their ability to hook up to large external displays and run a fully interactive desktop and applications over two displays at once. Let’s explore this further. What about being able wirelessly to hook up to a number of displays, some of them forming part of the Desktop, some perhaps temporary repositories to which a document window could be copied for viewing and possibly some touch-screen interactivity?

In response to Andy Hopper, I guess what I am indicating is:

  • I want an environmentally responsible computer, or ‘End User Device’, and one the energy requirement of which scales according to how much work, and what kind of work, I am doing with it.
  • I don’t like the idea of entrusting my bulk storage to the Internet, and needing access to the Internet to do any serious work, which is what the ‘thin client’ model suggests to me.
  • I would like to look beyond the ‘one size [laptop] fits all’ approach that to me is implied by the choices Defra has made for its staff.

I guess I’m asking for a lot, but there’s nothing new there!


How is Defra tackling climate change? — page links to science notes.

Computing & Information Processing for the Future of the Planet — four-page op-ed paper by Conrad Taylor in PDF form, prepared for a meeting of the BCS Geospatial Specialist Group on 10 July 2008

On the radical energy-saving architecture of the XO laptop, see A Conversation with Mary Lou Jepson (hardware designer of the XO) in ACM Queue.