Most of the modern computers are multicore computers. For example, the laptop used when writing this book has an Intel® i7-8565U processor that has four cores with two threads each.
What does this mean? Four cores on a processor allow performing four computational tasks in parallel. Four cores with two threads each are often counted as eight CPUs by system monitors. For the purposes of this chapter only the number of cores matters.
These cores share a common memory—the RAM of your laptop—and have individual memory in the form of cache memory:
The cache memory is used optimally by its core and is accessed at high speed, while the shared memory can be accessed by all cores of one CPU. On top, there is the computer's RAM memory and finally, the hard disk, which is also shared memory.
In the next section, we will see how a computational...
