PERF_ELAPSED_TIME

Description This counter type shows the total time between when the component or process started and the time when this value is calculated. The F variable represents the number of time units that elapse in one second. The value of F is factored into the equation so that the result can be displayed in seconds.
Generic type Difference
Formula (D0 - N0) / F, where D represents the current time, N represents the time the object was started, and F represents the number of time units that elapse in one second.
Average (Dx - N0) / F
Example System\ System Up Time

.