> forking 16 instances is going to be a lot heavier on memory

It really depends on how the application is designed. Fork operates through mmap and copy-on-write. It's extremely lightweight by default.

A well-designed fork-based application will already have everything necessary to run a given process into memory, not munge any of the existing shared memory, and only allocate and free memory associated with new events/connections/etc.

When programmed that way, individual forks are incredibly light on resources. All the workers are sharing the exact same core application code and logic in memory.