IBM Licenses Processors by Performance - More licenses required for Power6 processors

If you are migrating from Power5 to Power6 you will need additional VU licenses.

IBM Power6 processors will cost you 120 VUs per-processor licenses for the software running on the platform. An example used to calculate the cost; if you migrate from an 8-way Power5 server to an 8-way Power6 - you will need to increase from 800 VUs to 960 VUs. This amounts to 160 VU licenses.

IBM reportedly said that the price hike is justified as the Power6 processor performance is significantly greater than that of Power5. That is - you don't need as many Power6 processor cores to run the same workload that the Power5 required.

IBM's decision to license by CPU model and number of cores adds more complexity to managing software licenses across the enterprise.

The net-net - they want to maintain the same revenue streams even though technology is advancing and delivering more power for fewer chips.