User Guide

Contents

Sample After Value

For a custom event-based sampling data collection, set up the Sample After Value (SAV) that is a frequency with which the
Intel® VTune™
Profiler
interrupts the processor to collect a sample during hardware event-based data collection. SAV is measured as the number of events it takes to trigger a sample collection.
A Sample After Value that is too small causes the sampling interrupts to occur too frequently, which can lead to performance degradation and system instability.
VTune
Profiler
enforces a floor value to prevent such a behavior. The recommended value is 1000 samples per second per processor.
VTune
Profiler
sets the Sample After value for hardware events automatically. For predefined hardware-level analysis types, the Sample After value is displayed in the
Configure Analysis
window >
HOW
pane. You cannot edit the Sample After value provided in the table for each event. But during the data collection the
VTune
Profiler
may adjust it by a multiplier. The multiplier depends on the sampling interval value specified in the
HOW
pane.
To edit the default Sample After value, you need to create a custom hardware event-based analysis type (based on an existing type), add events, if required, and edit a Sample After value in the events table by selecting it as follows:
Sample After Value Configuration

Product and Performance Information

1

Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.

Notice revision #20110804