Comment by foobarchu
In cases where java is unavoidable and you're working with large blocks, it is possible to sort of skirt around the gc with certain kinds of large buffers that live outside the heap.
I've used these to great success when I had multiple long-lived gigabyte+ arrays. Without off-heap memory, these tended to really slow the gc down (to be fair, I didn't have top of the line gc algorithms because the openj9 jvm had been mandated)
Managing off heap memory in Java is pain even worse than manual memory management in C. Unlike C++ and Rust, Java offers no tools for manual memory management, and its idioms like frequent use of exceptions make writing such code extremely error prone.