As microprocessors get smaller and more powerful they will use more power to run – and the overhead this will use is expected to significantly reduce the effective performance of the chips. This “dark silicon” could account for as much as 50% of new chips’ capacity as early as next year.
In fact, for chips to keep up with Moore’s Law beyond the next generation or so of products will require a radical micro-architectural innovations and changes.
These are some of the findings presented in a paper entitled “Dark Silicon and the end of Multicore Scaling” presented at the International Symposium on Computer Architecture, which suggests that the number of transistors being squeezed on to ever-smaller chips will soon use more power than is economical.
Moore’s Law calls for a doubling of transistors on the chip every 18 months but, since 2005, this have been achieved by developing additional cores rather than trying to cram more transistors on to a single core, which has reached its effective limit.
Now, multi-core scaling may soon reach a limit as well, say researchers, because it will run into severe power limitations.
In just one year’s time, with 22nm chips, as much as 21% of a fixed-size chip must be powered off – and at 8nm, this limitation will grow to 50%.
As a result, over the next five generations of chips, only a 7,9-times average speedup will be possible.
The researchers believe that radical micro-architectural innovations will be necessary to avoid these power issues limiting microprocessor performance in the near future.