Is there an equivalent to apache's start-servers, spare-servers, and server-limit configuration options in BIND?
You need to edit the relevant startup script (based on your system) and pass in
-n <number_of_processes> to bind (or named).
-n #cpus Create #cpus worker threads to take advantage of multiple CPUs. If not specified, named will try to determine the number of CPUs present and create one thread per CPU. If it is unable to determine the number of CPUs, a single worker thread will be created.