From: Peter Kümmel (syntheticpp_at_[hidden])
Date: 2005-04-16 04:37:15
Andrei Alexandrescu (See Website For Email) wrote:
> Bob Bell wrote:
>> The end of Moore's law has been predicted for many years; I don't see
>> any reason to believe that processor speeds will stay stalled at 4GHz
>> for long.
Moore`s law is about "Number of components per integrated function" or
"Number of components per integrated circuit" (see original paper
The increasing of processor speed was only a "side effect".
> This times the reasons are more fundamentaal than ever before; an
> unforeseen limitation in the speed of light seems to be the culprit :o).
Increasing the size of a circuit there is no physical limit which
blocks Moore's law.
But your are right, the combination of the physical limits
"Number of components per area" and "speed of light" results in
a limited processor speed.
Here the theoretical upper limit of processor speed:
1. distance between to transistors: s = 10^-10 m (size of a atom)
2. Speed of light c = 3*10^8 m/s ~ 10^9 m/s (I'm interested in the upper limit)
travel time of a signal:
t = s / c
= 10^-10 m / (10^9 m/s)
= 10^(-10-9) s
= 10^-19 s
Processor speed 1/t:
1/t = 10^19 Hz
= 10^10 * 10^9 Hz
= 10 billion GHz
So there is much room to increase processor speed.