It seems that there is, in the works, a fully asynchronous CPU, you can read about it here:
http://www.arm.com/news/6936.htmlWhy is this important? Well, first of all, you computer spends about 99% of it's time waiting for you to do something. An asynchronous system would be literally computing on demand. This will save huge amounts of power, and reduce the cost of components and increase their expected lifetimes since they don't have to run all the time. As well, most of the time, your system is underutilized...that is, not only does it spend most of it's time waiting, but it also rarely needs all the computing umph that you have. For example, most word processing in a graphical interface could be done easily by a old 386 computer, but most people have orders of magnitude better computers because occasionally, they need that power to run a few processes quickly, like, say printing to a high-resolution printer. What asynchronous computing will give you is that extra power, when you need it.
For example, say you mostly do word processing...the computer will just fire up one processor...but when you want to play Doom 5, or Halo 3, it then uses a dozen processors to give you smooth 60 frames per second with more lighting effects than a Ridley Scott movie. But most of the time, your electrical utilization is about 1% of what most systems use today. This may not be too important to home users, but think about a company that has 500 people in a building, and they all have at least one computer they access...this adds up to a lot of savings for companies, and eventually cheaper products and services for you, and it means a great deal for the environment, as most of those computers are sucking up power 8-24 hours a day, and only really being used fully about 1% of that time, if that.
There are also some really interesting computing problems that are solved by a bunch of fully asynchronous CPUs, but that would probably bore most of the people here...
ttyl