This is exactly correct. IBM ships their POWER line of servers with anywhere from 4 to 40 physical CPUs (per Central Electronics Complex or “CEC”), and the number that are activated is directly proportional to the number the customer pays to license. Works pretty damn well when virtualization and scalability are important to the buyer.
Many of their OS’s, software products and other 3rd party software products that run on the system (i.e. Oracle) are also licensed by the number of activated CPU’s assigned to a particular workload.
Not only that, but now there a technology called POWER Enterprise Pools. Instead of having the processors or memory you purchased locked into one physical machine, you have a pool of memory and/or CPU activations that you can move between physical machines at will.