[jack_napier]

I'm thinking of writing a program that will need eight to properly test. I will not do that unless I have a Mac Pro.

I can't easily imagine what needs that level of simultaneous VMs unless it's clustering or some peer-to-peer application.

[antiRepublicrat]

I can't easily imagine what needs that level of simultaneous VMs unless it's clustering

Ding! I'd say minimum three front-ends, two file servers, domain controller and database. Plus I need a client within the VM's network.

Even without clustering it's not hard to imagine with a distributed n-tier system. For example a web front-end, business object server, authentication server, image server, ad front-end, content DB, ad DB, LDAP server.