When creating a DB2 instance, DB2 runs a small calibration test multiple times to assess the CPU speed. The average time from these tests are used to calculate the CPU speed. There is a bit of science to these tests. The tests are run within the duration of a quantum of time that the operating system scheduler provides to ensure the CPU calibration tests are valid regardless of how busy the system is when they run. Customers can change the CPU SPEED value to a desired value or let DB2 recalculate it by setting the value to -1 (negative 1). C.