I had a little fun and ran the branch on monster.dragonflybsd.org,
which is our 48-core opteron.
4 physical chips x 12-core per chip, no HT. 48 cpu cores total.
http://apollo.backplane.com/DFlyMisc/smt.txt
It made a valient effort but got a bit confused.
I can run anything you need on that box for testing purposes.
-Matt