On Wed, 17 Feb 2016 18:06:00 +0000, Ola Fosheim Grøstad wrote: > And well, with new materials, the potential for higher speeds. > These researchers managed to get a silicon-germanium transistor up to > 800Ghz (cryonic) and the article speaks of the possibility of running at > Thz. > > http://www.news.gatech.edu/2014/02/17/silicon-germanium-chip-sets-new- speed-record > > Moore's law deals with the number of transistors on the same chip. But > who cares if you can have faster and more?
Distance penalties. First there's the design issue of routing electrical impulses to different parts of the chip without interfering with other paths. You can solve that by making the chip even bigger, and you can partially address it with heavy duty constraint solvers. Then there's that pesky speed of electrical signal transmission. A bigger chip incurs that penalty more often. One thing you can do is simply replicate your CPU multiple times. We currently have multicore CPUs to do this in a convenient way, but this involves some caution with cache invalidation and shared memory. Muck about with scheduling and shared memory stuff and you could get more isolated parallelism, allowing cheaper manycore CPUs. Not sure if that would be much of a benefit.
