Why are CPU and GPU manufacturers trying to make transistors smaller and smaller instead of making the chips bigger so they can put more transistors?

Question

Why are CPU and GPU manufacturers trying to make transistors smaller and smaller instead of making the chips bigger so they can put more transistors?

In: 11

Answer 1

The speed of light limits the size of chips. With a 3 Ghz processor, light travels about an inch per cycle (electricity in silicon moves a bit slower than that). Anything that has to happen in one cycle can’t have a longer path than that.

You can get around this by putting in multiple cores, to an extent. You can split up a program so that each core handles separate tasks (threading), but there’s diminishing returns because they can’t share the tasks. If your program has 3 tasks, with one task taking 50 cycles and the others taking 25 cycles, then with one core it takes 100 cycles, with two cores it takes 50 cycles, with three cores it takes 50 cycles, and with 16 cores it still takes 50 cycles.