Silicon is almost at its limits. We are on the verge people, of breakaway computing power. Bank on it.
The genetic and molecular systems theorized about a few years ago are now in the R&D stages and the possibilities for both are astounding. For instance, the molecular computer will be a trinary deck. A trinary deck has the standard "On/Off" or "Yes/No" options like our normal everyday binary decks have but also will be able to have "ONOFF" or "YESNO" essentially giving the computer a "maybe".
What does this mean?
I will give an example of the increase in computing power:
You have a number, with 1 MILLION digits (thats 1,000,000 zeros on the number, not 1,000,000) and you ask the combined computing power of all the world to give all the factors of that number and it would take approximately 2.5 CENTURIES to compute.
You give that same number to a molecular computer and tell it to do the same exact thing and you have the results within 4 seconds.
Computers wont be clocked in Gigahertz or even Terahertz, but Exahertz, Zettahertz and Yottahertz. (A giga is 1 billion, tera is 1 trillion, peta is 1 quadrillion, exa is 1 quintrillion, zetta is 1 sextillion, yotta is 1 septillion or 1,000,000,000,000,000,000,000,000).
To put that in perspective. If you stacked every grain of sand on Earth (something on the order of 5 trillion) you would have a line of sand all the way to Neptune. If you had enough sand to equal a septillion you would have enough sand to make a line all the way to the nearest star (3.2 light years)....AND BACK. This is how big of a number we are talking about and when discussing speeds, its just going to get insane.
further, storage devices will become molecular as well reducing the need for moving parts and thus increasing the overall speed of the machine. Currently, your computer can only go as fast as the front side bus speeds and your hard drive (depending on what task you are performing).
Molecular (or genetic, both of which show much promise) computers are literally going to transform everything we know moreso than the microchip did, moreso than electricity did, moreso than pretty much any invention ever. Why? with these computers, calculations for things that are not currently possible can happen, not in a few hours, but in moments, real time. Weather will be able to be predicted...ACCURATELY, to over three hundred thousand years worldwide just to give you an example.
Not to mention the possibilities of the nano and quantum technologies being incorporated into the computing world.
It is truly a fascinating time to be alive.