GPU utilization

The meaning of GPU utilization in nvidia-smi raises a question for me. Assume the number of cores in a GPU is X. Which sentence is correct when we are talking about 70% utilization?

1- All cores are utilized by 70%.
2- only 70% of the cores are fully utilized.

Neither.

https://stackoverflow.com/questions/40937894/nvidia-smi-volatile-gpu-utilization-explanation/40938696#40938696

So is there any way to get a report on busy cores? I didn’t find such thing in the profiler either.

this depends on your definition of busy core :) overall, such questions magically disappear once you learned how GPU works. but in order to understand this material, you need to know how CPU works, which by itself means reading some hard-cover book, such as https://www.elsevier.com/books/computer-architecture/patterson/978-0-12-811905-1