Viewpoint

A Viewpoint is a preset result tab configuration that selects particular data collected during a performance analysis and enables you to focus on specific performance problems. When you select a viewpoint, you select a set of performance metrics the Intel® VTune™ Amplifier shows in the windows of the result tab. To select the required viewpoint, click the (change) link and use the drop-down menu at the top of the result tab:

Name of the analysis type you ran.

Name of the current viewpoint.

Viewpoint drop-down menu that displays a list of viewpoints available for the current analysis type. Click the (change) link to open the menu and select a viewpoint.

Viewpoint description icon. Click the question mark icon to read a short overview of the selected viewpoint.

Explore the table below to understand which viewpoints are available for each analysis type:

Viewpoint

Description

Analysis Type

Hotspots

Helps identify hotspots - code regions in the application that consume a lot of CPU time.

Advanced Hotspots, Basic Hotspots, Concurrency, Locks and Waits

Hotspots by CPU Usage

Helps identify hotspots - code regions in the application that consume a lot of CPU time. CPU time is broken down into CPU usage states: idle, poor, fair, and good.

Basic Hotspots, Concurrency, Locks and Waits

Hotspots by Thread Concurrency

Helps identify hotspots - code regions in the application that consume a lot of CPU time. CPU time is broken down into thread concurrency states: idle, poor, fair, good, and over.

Concurrency, Locks and Waits

Locks and Waits

Shows how your application is utilizing available CPU cores and helps identify the cause of ineffective utilization, for example: threads waiting too long on synchronization objects (locks), I/O, or timers while CPU cores are underutilized. CPU time is represented by bars colored according to the CPU utilization level during the wait.

Concurrency, Locks and Waits

Hardware Event Counts

Displays the event count for all collected processor events. While the Hardware Event Sample Counts viewpoint provides the actual number of samples collected for an event, Hardware Event Count viewpoint estimates the number of times this event occurred during the collection.

All hardware-level event-based sampling analysis types

Hardware Event Sample Counts

Displays the sample count for all collected processor events. While the Hardware Event Counts viewpoint estimates the number of times an event occurred during the collection, the Hardware Event Sample Counts viewpoint provides the actual number of samples collected for this event.

All hardware-level event-based sampling analysis types

Hardware Issues

Helps identify where the application is not making the best use of available hardware resources. This viewpoint displays metrics derived from hardware performance counters. Hover over the highlighted metrics values in the grid to read why the extreme value might represent a performance problem.

All hardware-level event-based sampling analysis types

General Exploration

Helps identify where the application is not making the best use of available hardware resources. This viewpoint displays metrics derived from hardware events. The Summary window reports the overall metrics for the entire execution along with explanations of the metrics. From the Bottom-up and Top-down Tree windows you can locate the hardware issues in your application. Cells are highlighted when potential opportunities to improve performance are detected. Hover over the highlighted metrics in the grid to see explanations of the issues.

Sandy Bridge/Ivy Bridge Analysis, Nehalem/Westmere Analysis, Knights Corner Platform Analysis types

Bandwidth

Helps identify where the application is generating significant bandwidth to DRAM. Memory bandwidth, in GB/sec, is plotted in the timeline, while events often associated with DRAM requests are shown in the grid. In the timeline, select a region of high bandwidth, and filter that region in. Use the grid to discover where in the code DRAM accesses are being generated.

Sandy Bridge/Ivy Bridge Bandwidth analysis type

QPI Bandwidth

Displays hardware event-based metrics to quantify QPI bandwidth over time and show code regions where the application is generating significant bandwidth across the QPI links. Transmit bandwidth, in GB/sec, is plotted over time in the timeline, while metrics for events often associated with DRAM requests are shown in the grid. Analyze the grid to discover where in the code QPI packets are generated.

Sandy Bridge/Ivy Bridge Analysis types with the Analyze Memory Bandwidth option enabled

CPU Frequency

Displays the time spent in different frequency modes and frequency transitions. Analyze the data in the grid to identify cores with the most time spent in high frequency modes. Spending more time in low frequency modes provides greater power savings.

Note

This viewpoint is available only for the analysis results collected on Linux* systems based on Intel® Xeon® processors.

CPU Frequency

CPU Sleep States

Displays the time spent in each sleep state and provides information on processor wake-ups: time and cause. Eliminate wake-ups where possible and maximize the time spent in the deepest sleep state to achieve lower power consumption.

Note

This viewpoint is available only for the analysis results collected on Linux* systems based on Intel Xeon processors.

CPU Frequency, CPU Sleep States

Task Time

Visualizes tasks, logical units of work on specific threads, based on ITT API annotations. Identify tasks with the highest execution time and analyze threads responsible for a particular task.

Any analysis type for a target using Task API

如需更全面地了解编译器优化,请参阅优化注意事项