Importing many 3ds files for bigger outdoor projects makes my dialux work extremely slow (unresponsive, slow calculation - 5minutes...).

I understand that calculation with many objects like trees will be slow, but would not expect the program to work as slow. Can it be a problem with my PC? i am using ASUS STRIX laptop G17 with i7 10750H CPU and RTX 2070 graphics card.

If it makes sense i would gladly upgrade the PC if that would mean i could do better looking calculations. But would need some confirmation first and maybe a recommendation regarding the needs of Dialux (CPU or GPU oriented rendering).