* Only one of the four CPU cores is busy servicing transactions. Said another way, 25% of the CPU cores are busy.

This will be our starting point for CPU subsystem performance analysis. The rest of this section will build from this point.

Have you ever heard someone say the IO subsystem needs to be balanced? Of course you have, because an IO subsystem can have very active devices and not very active devices. But as a DBA, it's very unlikely you have heard someone say the CPU subsystem needs to be balanced. That is because any available CPU core can service any transaction in the queue. Unlike an IO subsystem, where reading and writing must occur at an exact spot on a physical spindle, any CPU core can process any waiting transaction. This has massive implications.