I might want to add in reading the spec for the smb package for 5.1 they offer a base of only 2 CPU's per host so 2 per host up to 3 so if you have a low amount of VM's then this would be a good solution but if you have more then I would recommend more. We had a OECE training event last year using 5.0 with 2 CPU's (fast w/ cache and 4x cores) and with 20 VM's (DSS V6) was slow.