Processor Value Unit terminology

What does it all mean?


In the rapidly changing world of technology, old words may take on new meanings. Following are four key definitions that all IBM software sellers need to understand in order to fully explain IBM’s software licensing to customers:

Core - A functional unit within a computing device that interprets and executes software instructions.

Chip – electronic circuitry, containing but not limited to at least one core, on a silicon wafer.

Socket – the mount that secures a chip to a motherboard.

Processor – There is currently disagreement in the computer industry over the definition of a processor. IBM defines a processor as the core. For example, a dual-core chip has two processor cores on it.

What is a processor?

IBM, as do most middleware vendors, continues to define a processor as the core because this is where the software actually executes. Most hardware vendors, though now define the processor as a chip. This change began with the introduction of x86 dual-core chips in April, 2005.

Some people in the industry, especially hardware vendors, have suggested this point of customer confusion could be solved if middleware were licensed at the chip level instead of the core. This approach won’t satisfy customer requirements, though. With the power available in today’s processor cores, customers increasingly want to partition their systems so that an application runs in a subset of the processors in a server, and have the licensing structure support this. This is the reason IBM introduced sub-capacity licensing in April, 2005.

For an example, let’s look at a customer who has a server with two dual-core chips (4 processor cores) and only wants to run DB2 on one core. If per chip licensing were used, they would effectively have to license for both processor cores on that chip, not just the one the customer was actually running the middleware on. Leveraging sub-capacity licensing at the processor core level, however, they would only require DB2 to license at that level. This situation will worsen as the number of cores per chip continues to increase in the coming months and years.