If you make a processor twice as big, performance does not increase by a factor of two — it increases approximately by the square root. So doubling chip size doesn’t provide double the performance — it provides about 1.4 times the performance, an increase of 40 percent. This is called Pollack’s Rule (for Intel engineer Fred Pollack) and has been demonstrated in various single-core systems. Chip manufacturers strive to put several cores on a chip to increase this factor, thereby boosting speed and efficiency.
Multicore Demands Communications by Design
September 8, 2008