stat/clock is a SAP Parameter attribute which is used to control Clock for SAP statistic information. This is available within R/3 SAP systems depending on the version and release level.
Below is the standard documentation available and a few details of the attributes values .
stat/clock defines which clock is used for SAP statistics. There are two
clocks in the system: A clock based on gettimeofday and a p
latform-specific clock based on a hardware register. The second clock
has better resolution and is less expensive to call, but does not work
properly in all environments.
See SAP Parameter Documentation for full SAP documentation for this profile parameter.