Back in the last century, I designed the look and feel of a new American magazine called ‘Electronics Cooling’. It comes as no surprise to know that it’s title discloses its contents. No matter that I wasn’t told of its destination until the magazine had been completed and signed-off by the editor, resulting in a frantic and not entirely happy reshuffling to change its page size. Only after it had been printed did the American buyer see the English spelling throughout and especially on it’s cover. There in large 32 point Franklin Gothic Demi was ‘Characterisation’ using an ‘S’ instead of a ‘Z’. Oh well, I didn’t supply the copy!

Things used to be a lot quieter in those days. Desktop computers ran 32-bit chips at speeds measured in the tens of megahertz if you were lucky to have one so fast. On-board cooling was barely necessary, with one fan usually attached to the power supply unit and often sucking air in through the hole in the casing shared with the floppy disk drive aperture. Opening the case usually revealed a thick layer of fluff covering the whole motherboard.

Fat chance of this nowadays, it would all be burned off in no time, emulating a Sony laptop battery’s volatile nature. There is no doubt that the IBM Power 4 derived chips in my current machine run exceedingly hot. During the excesses of summer’s weather, even moving the mouse seemed to generate a speed-up of the internal cooling fans, almost like sitting on an electric motor bike and revving it up at the traffic lights. This first generation computer is only cooled by air, with 5 internal fans, whereas my wife’s later and faster version uses a combined liquid and air cooling, running a lot quieter as a result. When it first arrived I gave it a whole load of hard to do things to do and pressed my ear to the case to hear if it gurgled – it didn’t. Even so, if we start either computer in basic mode before the software controlling the fans is loaded, they soon spin up to maximum, emulating Concorde on full afterburner.

It is with some relief that chip and computer manufacturers seem to have grasped the cooling problem and are coming up with new answers other than bigger and loader fans. In the case of my chosen manufacturer, changing to a different chip supplier means losing a lot of heat even if they are running faster. The current Power 4’s are designed for servers, after all, in high throughput multi-tasking environments rather than sitting on a desktop a metre or so from your ear. As it is, even with all the best tricks computer manufacturers pull, underclocking the chips. liquid cooling, heat pipes and the rest, it seems that we will eventually have to have some form of phase change cooling installed as CPU’s get ever more hot.

This could have some interesting benefits. Phase change cooling involves literally changing the nature of one thing to another and in the process moving heat from one place to another. In its simplest form it is a miniature refrigeration unit sitting under the computer, that compresses a gas into a liquid which is pumped to the processor. Here, the heat makes the liquid evaporate, so absorbing the heat which is then pumped back to the compressor to be reconverted to gas and releasing the heat at the same time. Depending on the size of the compressor, the amount of cooling can be well below zero degrees centigrade which in turn means larger and faster CPUs can be used. Or for something else to be cooled.

Apple Computer have already linked up with Coca Cola and iTunes so could we be on the verge of a Mac with a built in ice dispenser? The excess heat could be diverted to keep coffee warm in winter. The Apple Maquatosh?