I can't exactly answer that question because I'm not even sure if the premise is true, but I do know that "memory to memory" copying is often offloaded entirely

I can't exactly answer that question because I'm not even sure if the premise is true, but I do know that "memory to memory" copying is often offloaded entirely off the CPU. Here's a technical overview of some of the technologies from 2017 https://www2.eecs.berkeley.edu/Pubs/TechRpts/2017/EECS-2017-2.pdf https://www2.eecs.berkeley.edu/Pubs/TechRpts/2017/EECS-2017-...