Harmony21 How can the playback speed not slow during the first preview? My computer is also not bad

Does anyone know how to improve computing resource utilization in harmony? I playback on my scenes often requires one play through at about 4 - 8 FPS before it can play back at real time (in this case at 24 FPS)

I am using dual XEON Platinum 8124+2080 TI

When previewing, the usage rate of 2080ti is only less than half, and the fps is only 9

Even if Disable full scene anti aliasing, Disable render caching is still the same