Careful, this is not Erlang. These are real threads, you won't be able to have thousands of them, more like 20 [1]. If most of them are idle, then you can maybe increase it to ~100. They come with a considerable overhead, so it's better to have one thread handle several I/O operations concurrently and in parallel, than to have one thread dedicated to only one I/O operation.

[1]: https://serverfault.com/questions/1012360/how-can-i-tell-the....