RTX64 Latency View

RTX64 Latency View displays a visual comparison of latency between Windows and RTX64 cores. System Timer Response Latency is measured as the total time from when a Subsystem timer interrupt sends a signal to when that signal is recognized by software running in an Interrupt Service Thread (IST). As shown in the diagram below, Latency is made up of Hardware latency, the time it takes for a signal to be recognized by an Interrupt Service Routine (ISR), and Software latency, the time it takes from ISR to the routine running in IST.

The tool repeatedly captures data over 1 second intervals and provides a graphical display of the maximum value for that period for each core. Accumulated Min, Max and Average values are also displayed per core. You can view latency values from 32-bit and/or 64-bit processes running on Windows cores and compare it to latency values for 64-bit processes running on RTSS cores. You can optionally add video and/or disk loads to selected cores, which simulate system activity in order to show more accurately the maximum latency times on a busy system.

Configuring and running a test in RTX64 Latency View

1. Click Start > All Programs > IntervalZero RTX64 Latency View > RTX64 Latency View.
2. The RTX64 Latency View dialog appears. Click the configure icon to expand the Configure menu.

3. The Configure menu displays the total number of cores configured on your system. To select the Windows and RTSS cores you want to include in the performance test, click on a core indicator:

• Windows – click on a Windows core to select it. You can toggle 32-bit (aqua blue), 64-bit (dark blue), or unassigned (light gray).

• RTSS – click on a RTSS core to select. You can toggle 64-bit RTSS cores or unassigned.

NOTE: Dark gray indicates that a core is not selectable.

4. Optionally, click to add a Video or Disk load. You can also add loads while a test is running.
5. Once you have finished configuring your test, click the start icon. Graphs display live results in the main RTX64 Latency View window, based on selected Windows and RTSS cores.

Latency View Options

Option	Icon	Description
Run Test		Run the latency test with the selected cores.
Stop Test		Stop the current test.
Pause Test		Pause the current test without losing existing data.
Save Log File		Save test results to a log file.
Configure Test		Select the Windows and RTSS cores to include in the latency comparison.
Toggle Sound		The timer function toggles the output state of the system speaker port each time it is called. Since the timer function is called periodically, this results in a tone with a period equal to one half of the timer setting value. The system timer is set to 1 ms, resulting in a 500 Hz tone.
Reset		Reset accumulated statistics.
Help		View Help information on the Latency View tool.