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Terahertz processor speed of light

Last response: in CPUs
October 7, 2011 1:30:17 PM

Surely light travels 0.3 metres per nanosecond.

1 tera herz requires 1nanosecond / 1000. so light can only travel 0.0003 metres (1/3 millimetre) in that time.
Or have I got my powers of ten wrong?
Surely this will be a limitation on chip design - light is too slow for us??
a b à CPUs
October 7, 2011 1:49:55 PM

Yes, your math is correct. But we already see 250,000ish transistors in a 1/3mm radius so you have to factor that in also.

Ray Kurtzweil deduced that the theoretical limit is over 5*10^50 operations per second, a lot more than a terahertz...'s_law#cite_note-Kurzweil_2005-59
a b à CPUs
October 7, 2011 2:33:45 PM

Yes, the Speed of Light is a limiting factor, assuming c is in fact constant [which is currently being tested, as some results indicate this is not the case...]. The REAL limiting factor though is the space between chip components, as you start to increase latency as distances increase.