On Mon, 23 Mar 2009, Thor Lancelot Simon wrote:
QEMU (or, at least, 'Q' on OS X, which uses QEMU as its guts) supports up to 128 CPUs, in 32 or 64 bit x86 emulation.
I've played with that some time ago, see http://kerneltrap.org/index.php?q=mailarchive/netbsd-tech-kern/2005/12/22/292131 - Hubert