Unity Game Optimization - Third Edition

Garbage collection

The GC has an important job, which is to ensure that we don't use more managed heap memory than we need, and that memory that is no longer needed will be automatically deallocated. For instance, if we create GameObject and then later destroy it, the GC will flag the memory space used by GameObject for eventual deallocation later. This is not an immediate process, as the GC only deallocates memory when necessary.

When a new memory request is made, and there is enough empty space in the managed heap to satisfy the request, the GC simply allocates the new space and hands it over to the caller. However, if the managed heap does not have room for it, then the GC will need to scan all of the existing memory allocations for anything ...