Energy Analysis User Guide

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ID 767268
Date 5/25/2022
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Document Table of Contents
Document Table of Contents x
Energy Analysis User Guide
Energy Analysis User Guide x
Energy Analysis Workflows Build and Manage Energy Analysis Driver Intel® SoC Watch Command-line Tool Options Run Energy Analysis Run Energy Analysis Using Intel® System Studio Energy Analysis Metrics Reference Legal Information
Build and Manage Energy Analysis Driver x
Preparing a Target Linux* System for Energy Analysis Preparing a Target Android* System for Energy Analysis Preparing a Target Windows* System for Energy Analysis
Run Energy Analysis x
View Energy Analysis Data with Intel® VTune™ Profiler Interpret Energy Analysis Data with Intel® VTune™ Profiler Analyze Overall Statistics Identify Cores with Highest Time Spent in C0 States
Run Energy Analysis Using Intel® System Studio x
View Energy Analysis Data with Intel® System Studio Import Energy Analysis Results into Intel® System Studio
Energy Analysis Metrics Reference x
Available Core Time C-State D0i<i>x</i> States DRAM Self Refresh Energy Consumed (mJ) Idle Wake-ups P-State S0i<i>x</i> States Temperature Timer Resolution Total Time in C0 State Total Time in Non-C0 States Total Time in S0 State Total Wake-up Count Wake-ups Wake-ups/sec per Core
Energy Analysis User Guide

Interpret Energy Analysis Data with Intel® VTune™ Profiler

Identify causes of energy waste on target systems by opening your energy analysis results with Intel VTune Profiler.

After you collect energy analysis data on your target system, using the Intel® SoC Watch collector, you can import a result file (*.pwr ) to Intel® VTune™ Profiler on your host system. Energy analysis data is opened in the Platform Power analysis viewpoint.

To interpret the performance data provided during the energy analysis, you may follow the steps below:

  1. Analyze overall statistics.

  2. Identify cores with the highest time spent in C0 state.

Analyze Overall Statistics

Use the Summary window to view statistics on the overall collection run time execution per power analysis metrics. Viewing the top statistics and histograms for a particular metric is a good starting point. Focus on decreasing the causes of core wake-up and increasing the time that the core spends in the higher sleep states.

For example, this Top Core C-State by State diagram shows that the core was awake for approximately 10 seconds of the total collection time (time in CC0 state). Use the Profiled Entity drop-down to view the C-state data for other cores. Explore the histogram to analyze the time spent in each sleep state.

TIP:

Click the Details link next to the table or graph title on the Summary tab to view more information about that metric in another tab.

Identify Cores with Highest Time Spent in C0 States

Switch to the C-State Residency/Wakeups window and the Core C-State tab to identify cores with the highest time spent in the active C0 state. Spending more time in deeper sleep states (C1-Cn) provides greater power savings.

By default, VTune Profiler displays data grouped by core and sorted by CPU time spent in the deepest C-state in the ascending order. For the example below, over 30% of the time was spent in the CC0 active state for both cores.

Use the timeline view to understand when state transitions occur. Hover over a chart point to view the sleep states details for the particular moment of time. The deeper the color of the chart, the deeper the sleep state of the CPU. Select a region of the graph and zoom into the selection to see detailed sleep state transitions.

Parent topic: Run Energy Analysis
Level Two Title