[brirec]

Not necessarily, but often enough that the most expensive part in a mid range or high end gaming PC is an accelerator card meant to offload certain forms of computation that the CPU can't do as fast...

Or perhaps the h.264/h.265 codecs built into modern CPUs and GPUs?

And this isn't at all a new phenomenon, either. We've been using accelerators and coprocessors (as they were often originally known) for decades.