The computer has two cpu and each cpu has 24 cores.The problem is when build lighting (bake lightmap) only one cpu working in full ,the anther is idle.
Go to editor preferences=>lighting builds=> tick Enable multithreaded light encoding and multithreaded shadowmap encoding
Actually,epic hasn’t implement this function on the windows platform.
There’s something need to do :Engine\Source\Runtime\Core\Private\Windows.
It doesn’t work actually,and i find the reason.
Thanks for your answer.