bballad, while it is true that most modern UN*X systems support SMP, I would not call OpenBSD a modern UN*X, consequently:

http://www.openbsd.org/faq/faq8.html#SMP

It still lacks SMP support. Net and FreeBSD still have very bleh SMP support, really the only BSD with "industrial strength" SMP support would be BSDi. AIX, Solaris, HP-UX, IRIX, etc of course all offer SMP support ranging from very good to industry leading.

For comparison, Win2k Server supports 4 CPUs, Adv Server 8, Datacenter 16|32 naturally win2k standard supports 2 CPUs symmetrically. These numbers are essentially the same for 2003 with the exception of the datacenter support, which is now up to 64 CPUs.

BeOS used to offer fine SMP support, shame it more or less died, for dealing with only 2 CPUs BeOS seemed, the most efficient at least as far as x86 is concerned.

QNX also features exceptionally efficient SMP support.

As far as common stuff is concerned, Linux has supported SMP for a while now, but I have had a few engineers where I work say that 2k and 2003 are a little smarter about threading.

hope this helps.

catch