Yes, you can start the server with any number of slave processors. As long as you're not writing data to global namespace (i.e, if you can keep your code purely functional), then as pointed out above, one can use the "peach" (parallel each) operator [1] to parallelize execution. Further you also get the "distributed each" to distribute load amongst multiple processes instead of threads [2]
[1] http://code.kx.com/wiki/Reference/peach
[2] http://code.kx.com/wiki/Reference/peach#Peach_using_multiple...