Intel® Advisor Tutorial: Use the Automated Roofline Chart to Make Optimization Decisions

ID 758351
Date 12/04/2020

Intel® Advisor Tutorial for Using the Automated Roofline Chart to Make Optimization Decisions

This tutorial - and C++ sample application you can use to follow along - show how to use the Intel® Advisor automated Roofline chart to visualize actual performance against hardware-imposed performance ceilings, as well as determine the main limiting factor (memory bandwidth or compute capacity), thereby providing an ideal roadmap of potential optimization steps.

Intel® Advisor provides tools to help ensure your Fortran, C and C++ native/managed applications realize full performance potential on modern processors (for full list, see release notes):

  • Vectorization Advisor is a vectorization optimization tool that lets you identify high-impact, underoptimized loops, what is blocking vectorization, and where it is safe to force vectorization. It also provides code-specific how-can-I-fix-this-issue recommendations.

  • Roofline Analysis visualizes actual performance against hardware-imposed performance ceilings (rooflines). It provides insights into where the bottlenecks are, which loops are worth optimizing for performance, what are the likely causes of bottlenecks and what should be the next optimization steps.

  • Threading Advisor is a fast-track threading design and prototyping tool that lets you analyze, design, tune, and check threading design options without disrupting your normal development.

  • Offload Modeling is a modeling tool that lets you to identify high-impact opportunities to offload to GPU as well as the areas that are not advantageous to offload.

  • Flow Graph Analyzer is a visual prototyping tool that lets you represent and analyze performance for applications that use the Intel® oneAPI Threading Building Blocks flow graph interfaces.

This document was last updated for the Intel® Advisor 2020 product release. If you are using this tutorial with a higher version of Intel Advisor, you may see differences in workflow and analysis type names and user interface design.

About This Tutorial

This tutorial for shows how to:

  • Run a Roofline analysis.

  • Focus on the Roofline chart data of most interest.

  • Interpret Roofline chart data.

  • Use Roofline chart data interpretations to make optimization decisions.


This is an advanced Vectorization Advisor tutorial. See Intel® Advisor Tutorials for basic Vectorization Advisor tutorials that include quick start and basic operations information.

Estimated Duration

20 minutes.

Learning Objectives

After you complete this tutorial, you should be able to:

  • Identify compiler/linker options that produce the most accurate and complete Vectorization Advisor analysis results.

  • Run a Roofline analysis.

  • Show/hide a Roofline chart.

  • Use various Roofline chart controls.

  • Use the Roofline chart to identify which loops are the best candidates for optimization.

  • Load Intel Advisor snapshots.

More Resources

See Roofline Analysis in Intel® Advisor 2017 for a video that essentially covers the same content as this tutorial, but in more conceptual depth.

The concepts and procedures in this tutorial apply regardless of programming language; however, a similar tutorial using a sample application in another programming language may be available at Intel® Software Documentation Library.

These sites also offer tutorials for other Intel products.

In addition, you can find more resources in: