Sampling Interval

Configure the amount of wall-clock time the Intel® VTune™ Amplifier waits before collecting each sample (sampling interval).

The sampling interval is used to calculate the target number of samples and the Sample After value. You may change the default sampling interval as follows:

Click the New Analysis button on the VTune Amplifier toolbar.
The Choose Target and Analysis Type configuration window opens with the Analysis Type tab active.
Select a predefined analysis type from the left pane or create a custom analysis type.
Note

For predefined analysis types, the sampling interval configuration is available for all Algorithm analysis types and some of the Microarchitecture analysis types.
From the configuration pane on the right, use the CPU sampling interval, ms field to specify the required interval.
For user-mode sampling and tracing types, specify a number (in milliseconds) between 1 and 1000. Default: 10ms. For hardware event-based sampling types, specify a number between 0.01 and 1000. Default: 1ms.

To determine an appropriate sampling interval, consider the duration of the collection, the speed of your processors, and the amount of software activity. For instance, if the duration of sampling time is more than 10 minutes, consider increasing the sampling interval to 50 milliseconds. This reduces the number of interrupts and the number of samples collected and written to disk. The smaller the sampling interval, the larger the number of samples collected and written to disk.

The minimal value of the sampling interval depends on the system:

10 milliseconds for Windows* systems with a single CPU
15 milliseconds for Windows* systems with multi-core CPUs
10 milliseconds for Linux* 2.4 kernels
1,2,4 milliseconds for new Linux >= 2.6 kernels depending on the vendor

Sampling Interval

Note

See Also