Seven Concurrency Models in Seven Weeks

Parallel Architecture

Although there’s a tendency to think that parallelism means multiple cores, modern computers are parallel on many different levels. The reason why individual cores have been able to get faster every year, until recently, is that they’ve been using all those extra transistors predicted by Moore’s law in parallel, both at the bit and at the instruction level.

Bit-Level Parallelism

Why is a 32-bit computer faster than an 8-bit one? Parallelism. If an 8-bit computer wants to add two 32-bit numbers, it has to do it as a sequence of 8-bit operations. By contrast, a 32-bit computer can do it in one step, handling each of the 4 bytes within the 32-bit numbers in parallel.

That’s why the history of computing has seen ...