I introduce myself, my name is Kepa and it's my first message in the forum, I wanted to ask for help with a problem that I have when it comes to rendering via CPU. I attached image, of what I comment. As I commented the problem arises when I render through CPU, I have a workstation with a Dual Xeon 2699 V3-72 Processing threads, when I shoot render in Blender does not use more than 20%, as you will see in the attached image I had to correct it inside Of the performance section of the render tab, the auto threads detected by default puts me 36, that is half of them, I put 72 and nothing, is useless. I do not know if it is due to a Blender problem or that, I work under Max and with the rendering engine works 100% CPU I understand that it is Blender problem. Any help would be appreciated.
From your screenshot, you can see that you are only rendering 12 tiles. If you have 72 hyperthreads, then 12 tiles / 72 threads ~= 16% utilisation. Options:
Render the full image, instead of small fraction that you are.
Reduce the render tile size so that you have more tiles rendering at once.