• 2021.1
  • 12/04/2020
  • Public Content

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
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
    chart data of most interest.
  • Interpret
    chart data.
  • Use
    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
  • Use various
    chart controls.
  • Use the
    chart to identify which loops are the best candidates for optimization.
  • Load
    Intel Advisor
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.

Product and Performance Information


Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.