Both KSRTM (Kernel System Response Time Measurement) and SRTM (System Response Time Measurement) measure timer latencies. While KSRTM provides detailed information about the source of the worst-case latency, it measures only the time to the beginning of the Interrupt Service Routine (ISR). SRTM measures the total time to an RTSS program's timer handler (i.e., a full thread context); it is the more realistic measurement of latencies encountered by RTSS applications.
The worst-case SRTM for the RTX64 environment (srtm.rtss) reported latencies range from 2 to 20 microseconds on most Pentium-based systems. The worst-case SRTM for the Windows environment (srtm.exe) reported latencies range from 30 to 100 microseconds on most Pentium-based systems.
