I realize this is coming 2 weeks after this has been discussed, but it is important information:
The SMP files for Novell 4.11 are included, but there are only a couple of applications that can use the 2nd processor: GroupWise 5.x, Novell Webserver. Also, you will not be able to auto-recover after an abend while using SMP. And SMP will likely cause you a few abends. If you scour support.novell.com, you'll find documentation of trouble ticktets where Novell actually comes out and says "Don't use SMP with Netware 4.11!" I can't say for sure whether your motherboard will be compatible with the MPS14.PSM (platform support module).
SMP works great with 5.x. Load balances threads across CPU's. Very stable. I have used it extensively. Just be sure that your processors are the same model and stepping.