INtime timestamp counter
Compared to the low-level counters, the INtime timestamp counter allows significantly more precise time measurement.
The timestamp counter is a facility which is accessible from all nodes of a host, and Windows via NTX. The best possible source is automatically configured in order to provide a counter which is coordinated between the different nodes (the sources run at the same frequency) and if possible synchronized (in other words returns the same value from each node at a given instant). Where possible the source used is the system HPET (High-Precision Event Timer, a feature of many PC chipsets providing a 64-bit counter and programmable timer feature), but if the HPET is not available the CPU Time Stamp Counter (TSC) is used.
GetRtTimestampInfo returns details of the timestamp counter used on this node. Amongst other information like the source of the counter, the period of a counter increment is returned in femtoseconds.
GetRtTimestampCounter returns the actual value of the timestamp counter. This value needs to be multeplied by the counter increment in femtoseconds returned by GetRtTimestampInfo in order to get an absulute time.