How come a CPU has very few cores compared to a GPU that has thousands of cores and what causes GPU cores to be so small?

Question

How come a CPU has very few cores compared to a GPU that has thousands of cores and what causes GPU cores to be so small?

In: Technology

Answer 1

CPU can perform several different operations. For example you can use a CPU to perform addition, multiplication, subtraction and division. Hence a CPU can do a large variety of operations but not very fast.

GPUs on the other hand can only do a handful of operations: addition operations and they do it extremely fast. They have thousands of small cores that can only do addition but much quicker than a CPU. So if you have a bunch of addition operations to be done, you send them over to your GPU and split them across all the thousands of cores and each core does the computation fast and quick.

Note the actual operations performed by a CPU and GPU have different names. I used addition, subtraction, etc because this is ELI5

Also Note GPU tasks are not exactly split across all the cores like I said. The actual mechanism is a bit more complicated.