User Guide

Intel® VTune™ Profiler User Guide

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Date 12/16/2022
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Document Table of Contents
Document Table of Contents x
Intel® VTune™ Profiler User Guide
Intel® VTune™ Profiler User Guide x
Introduction Install Intel® VTune™ Profiler Open Intel® VTune™ Profiler Set Up Project Set Up Analysis Target Analyze Performance Intel® VTune™ Profiler Command Line Interface API Support Troubleshooting Reference Notices and Disclaimers
Introduction x
What's New in Intel® VTune™ Profiler Tuning Methodology Tutorials and Samples Notational Conventions Get Help Product Website and Support Related Information
Install Intel® VTune™ Profiler x
Sampling Drivers Set Up System for GPU Analysis Verify Intel® VTune™ Profiler Installation on a Linux* System Install VTune Profiler Server Security Best Practices
Set Up System for GPU Analysis x
Rebuild and Install the Kernel for GPU Analysis Rebuild and Install Module i915 for GPU Analysis on CentOS* Rebuild and Install Module i915 for GPU Analysis on Ubuntu*
Install VTune Profiler Server x
Set Up Transport Security Configure User Authentication/Authorization
Open Intel® VTune™ Profiler x
Get Started with Intel® VTune™ Profiler Intel® VTune™ Profiler Graphical User Interface Web Server Interface Microsoft Visual Studio* Integration Eclipse* and Intel System Studio IDE Integration Containerization Support macOS* Support
Containerization Support x
Run VTune Profiler in a Container Profile Container Targets from the Host
Set Up Project x
WHERE: Analysis System WHAT: Analysis Target HOW: Analysis Types Search Directories
WHERE: Analysis System x
Analysis System Options
WHAT: Analysis Target x
Analysis Target Options
Search Directories x
Search Order
Set Up Analysis Target x
Prepare Application for Analysis Windows* Targets Linux* Targets Embedded Linux* Targets FreeBSD* Targets QNX* Targets Managed Code Targets Android* Targets Intel® Xeon Phi™ Processor Targets Targets in Virtualized Environments Targets in a Cloud Environment Arbitrary Targets Embedded System Targets
Windows* Targets x
Install the Sampling Drivers for Windows* Targets Debug Information for Windows* Application Binaries Compiler Switches for Performance Analysis on Windows* Targets Debug Information for Windows* System Libraries Add Administrative Privileges
Linux* Targets x
Build and Install the Sampling Drivers for Linux* Targets Debug Information for Linux* Application Binaries Compiler Switches for Performance Analysis on Linux* Targets Enable Linux* Kernel Analysis Resolution of Symbol Names for Linux-Loadable Kernel Modules Analyze Statically Linked Binaries on Linux* Targets Set Up Remote Linux* Target
Set Up Remote Linux* Target x
Set Up Linux* System for Remote Analysis Configure SSH Access for Remote Collection Search Directories for Remote Linux* Targets Temporary Directory for Performance Results on Linux* Targets
Embedded Linux* Targets x
Configure Yocto Project* and VTune Profiler with the Integration Layer Configure Yocto Project*/Wind River* Linux* and Intel® VTune™ Profiler with the Intel System Studio Integration Layer Configure Yocto Project* and Intel® VTune™ Profiler with the Linux* Target Package
FreeBSD* Targets x
Set Up FreeBSD* System
Managed Code Targets x
.NET* Targets Windows Store Application Targets Go* Application Targets
Android* Targets x
Build and Install Sampling Drivers for Android* Targets Set Up Android* System Enable Java* Analysis on Android* System Prepare an Android* Application for Analysis Analyze Unplugged Devices Search Directories for Android* Targets
Targets in Virtualized Environments x
Profile Targets on a VMware* Guest System Profile Targets on a Parallels* Guest System Profile Targets on a KVM* Guest System Profile Targets on a Xen* Virtualization Platform Profile Targets in the Hyper-V* Environment
Profile Targets on a KVM* Guest System x
Profile KVM Kernel Modules from the Host Profile KVM Kernel and User Space on the KVM System Profile KVM Kernel and User Space from the Host
Analyze Performance x
User-Mode Sampling and Tracing Collection Hardware Event-based Sampling Collection Performance Snapshot Algorithm Group Microarchitecture Analysis Group Parallelism Analysis Group Input and Output Analysis Accelerators Analysis Group Platform Analysis Group Hybrid CPU Analysis Source Code Analysis Custom Analysis Energy Analysis Code Profiling Scenarios Control Data Collection Manage Data Views Manage Result Files
Hardware Event-based Sampling Collection x
Allow Multiple Runs or Multiplex Events Hardware Event-based Sampling Collection with Stacks
Algorithm Group x
Hotspots Analysis for CPU Usage Issues Anomaly Detection Analysis (preview) Memory Consumption Analysis
Hotspots Analysis for CPU Usage Issues x
Hotspots View
Anomaly Detection Analysis (preview) x
Anomaly Detection View
Memory Consumption Analysis x
Memory Consumption and Allocations View
Microarchitecture Analysis Group x
Microarchitecture Exploration Analysis for Hardware Issues Memory Access Analysis for Cache Misses and High Bandwidth Issues
Microarchitecture Exploration Analysis for Hardware Issues x
Microarchitecture Exploration View Microarchitecture Pipe
Memory Access Analysis for Cache Misses and High Bandwidth Issues x
Memory Usage View
Parallelism Analysis Group x
Threading Analysis HPC Performance Characterization Analysis
Threading Analysis x
Threading Efficiency View
HPC Performance Characterization Analysis x
HPC Performance Characterization View
Input and Output Analysis x
Analyze Platform Performance Analyze DPDK Applications Analyze SPDK Applications Analyze Linux Kernel I/O
Accelerators Analysis Group x
GPU Offload Analysis Aspects of the GPU Offload Analysis Configure the Analysis Run the Analysis Run from Command Line Analyze Multiple GPUs Analyze Data Transfer Between Host and Device Examine Energy Consumption by your GPU Support for SYCL* Applications using oneAPI Level Zero API Support for DirectX Applications GPU Compute/Media Hotspots Analysis (Preview) CPU/FPGA Interaction Analysis
GPU Compute/Media Hotspots Analysis (Preview) x
GPU Compute/Media Hotspots View
CPU/FPGA Interaction Analysis x
CPU/FPGA Interaction View
Platform Analysis Group x
System Overview Analysis Platform Profiler Analysis
System Overview Analysis x
Analyze Interrupts Analyze Latency Issues
Platform Profiler Analysis x
Platform Profiler View
Custom Analysis x
Custom Analysis Options
Custom Analysis Options x
Highly Accurate CPU Time Data Collection Hardware Event List Linux* and Android* Kernel Analysis Sampling Interval Sample After Value
Hardware Event List x
Hardware Event Skid Instructions Retired Event Precise Events
Energy Analysis x
Run Energy Analysis View Energy Analysis Data with Intel® VTune™ Profiler Interpret Energy Analysis Data with Intel® VTune™ Profiler
Code Profiling Scenarios x
Java* Code Analysis Python* Code Analysis Intel® Threading Building Blocks Code Analysis MPI Code Analysis OpenSHMEM* Code Analysis with Fabric Profiler GPU Application Analysis on Intel® HD Graphics and Intel® Iris® Graphics Frame Data Analysis Task Analysis
GPU Application Analysis on Intel® HD Graphics and Intel® Iris® Graphics x
GPU OpenCL™ Application Analysis Intel® Media SDK Program Analysis
Control Data Collection x
Finalization Pause Data Collection Limit Data Collection Generate Command Line Configuration from GUI Minimize Collection Overhead Import External Data
Import External Data x
Use a Custom Collector Create a CSV File with External Data Import Linux Perf* Trace with VTune Profiler Metrics Examples of CSV Format and Imported Data
Manage Data Views x
Switch Viewpoints Control Window Synchronization View Stacks Manage Grid Views Manage Timeline View Change Threshold Values Choose Data Format Group and Filter Data View Data on Inline Functions Analyze Loops Stitch Stacks for Intel® oneAPI Threading Building Blocks or OpenMP* Analysis Search for Data
View Stacks x
Call Stack Mode Metrics Distribution Over Call Stacks
Manage Result Files x
VTune Profiler Filenames and Locations Import Results and Traces into VTune Profiler GUI Compare Results
Compare Results x
Compare Source Code View Comparison Data
View Comparison Data x
Comparison Summary Bottom-up Comparison Top-down Tree Comparison
Intel® VTune™ Profiler Command Line Interface x
vtune Command Syntax vtune Actions Run Command Line Analysis Work with Results from Command Line Generate Command Line Reports Command Line Usage Scenarios Command Line Interface Reference Report Problems from Command Line
Run Command Line Analysis x
performance-snapshot Command Line Analysis hotspots Command Line Analysis anomaly-detection Command Line Analysis threading Command Line Analysis memory-consumption Command Line Analysis hpc-performance Command Line Analysis uarch-exploration Command Line Analysis memory-access Command Line Analysis tsx-exploration Command Line Analysis tsx-hotspots Command Line Analysis sgx-hotspots Command Line Analysis gpu-hotspots Command Line Analysis gpu-offload Command Line Analysis graphics-rendering Command Line Analysis fpga-interaction Command Line Analysis io Command Line Analysis system-overview Command Line Analysis platform-profiler Command Line Analysis runsa/runss Custom Command Line Analysis Configure Analysis Options from Command Line
Configure Analysis Options from Command Line x
Collect System-Wide Data from Command Line Collect Data on Remote Linux* Systems from Command Line Configure GPU Analysis from Command Line Specify Search Directories from Command Line Specify Result Directory from Command Line Pause Collection from Command Line Manage Analysis Duration from Command Line Limit Data Collection from Command Line
Work with Results from Command Line x
View Command Line Results in the GUI Import Results from Command Line Re-finalize Results from Command Line
Generate Command Line Reports x
Summary Report Hotspots Report Hardware Events Report Callstacks Report Top-down Report gprof-cc Report Difference Report View Source Objects from Command Line Save and Format Command Line Reports Filter and Group Command Line Reports
Command Line Usage Scenarios x
Use VTune Profiler Server in Containers Android* Target Analysis from the Command Line OpenMP* Analysis from the Command Line Java* Code Analysis from the Command Line
Command Line Interface Reference x
Option Descriptions and General Rules allow-multiple-runs analyze-kvm-guest analyze-system app-working-dir call-stack-mode collect collect-with column command cpu-mask csv-delimiter cumulative-threshold-percent custom-collector data-limit discard-raw-data duration filter finalization-mode finalize format group-by help import inline-mode knob kvm-guest-kallsyms kvm-guest-modules limit loop-mode mrte-mode no-follow-child no-summary no-unplugged-mode quiet report report-knob report-output report-width result-dir resume-after return-app-exitcode ring-buffer search-dir show-as sort-asc sort-desc source-object source-search-dir stack-size start-paused strategy target-install-dir target-system target-tmp-dir target-duration-type target-pid target-process time-filter trace-mpi user-data-dir verbose version
API Support x
Instrumentation and Tracing Technology APIs JIT Profiling API System APIs Supported by Intel® VTune™ Profiler
Instrumentation and Tracing Technology APIs x
Basic Usage and Configuration Instrumentation and Tracing Technology API Reference
Basic Usage and Configuration x
Configure Your Build System Attach ITT APIs to a Launched Application Instrument Your Application Minimize ITT API Overhead View Instrumentation and Tracing Technology (ITT) API Task Data in Intel® VTune™ Profiler
Instrumentation and Tracing Technology API Reference x
Domain API String Handle API Collection Control API Thread Naming API Task API Frame API Histogram API User-Defined Synchronization API Event API Counter API Load Module API Memory Allocation APIs
JIT Profiling API x
Using JIT Profiling API JIT Profiling API Reference
JIT Profiling API Reference x
iJIT_NotifyEvent iJIT_IsProfilingActive iJIT_ GetNewMethodID
Troubleshooting x
Best Practices: Resolve Intel® VTune™ Profiler BSODs, Crashes, and Hangs in Windows* OS Error Message: Application Sets Its Own Handler for Signal Error Message: Cannot Enable Event-Based Sampling Collection Error Message: Cannot Collect GPU Hardware Metrics Error Message: Cannot Collect GPU Hardware Metrics for the Selected GPU Adapter Error Message: Cannot Load Data File Error Message: Cannot Locate Debugging Information Error Message: Cannot Open Data Error Message: Client Is Not Authorized to Connect to Server Error Message: Root Privileges Required for Processor Graphics Events Error Message: No Pre-built Driver Exists for This System Error Message: Not All OpenCL™ API Profiling Callbacks Are Received Error Message: Problem Accessing the Sampling Driver Error Message: Required Key Not Available Error Message: Scope of ptrace System Call Is Limited Error Message: Stack Size Is Too Small Error Message: Symbol File Is Not Found Problem: Analysis of the .NET* Application Fails Problem: Cannot Access VTune Profiler Documentation Problem: CPU time for Hotspots or Threading Analysis is Too Low Problem: 'Events= Sample After Value (SAV) * Samples' Is Not True If Multiple Runs Are Disabled Problem: Guessed Stack Frames Problem: GUI Hangs or Crashes Problem: Inaccurate Sum in the Grid Problem: Information Collected via ITT API Is Not Available When Attaching to a Process Problem: No GPU Utilization Data Is Collected Problem: Same Functions Are Compared As Different Instances Problem: Skipped Stack Frames Problem: Stack in the Top-Down Tree Window Is Incorrect Problem: Stacks in Call Stack and Bottom-Up Panes Are Different Problem: System Functions Appear in the User Functions Only Mode Problem: VTune Profiler is Slow to Respond When Collecting or Displaying Data Problem: VTune Profiler is Slow on X-Servers with SSH Connection Problem: Unexpected Paused Time Problem: {Unknown Timer} in the Platform Power Analysis Viewpoint Problem: Unknown Critical Error Due to Disabled Loopback Interface Problem: Unknown Frames Problem: Unreadable Text on macOS* Problem: Unsupported Microsoft* Windows* OS Warnings about Accurate CPU Time Collection
Reference x
User Interface Reference CPU Metrics Reference GPU Metrics Reference OpenCL™ Kernel Analysis Metrics Reference Energy Analysis Metrics Reference Intel Processor Events Reference
User Interface Reference x
Context Menu: Grid Context Menus: Call Stack Pane Context Menus: Project Navigator Context Menus: Source/Assembly Window Dialog Box: Binary/Symbol Search Dialog Box: Source Search Hot Keys Menu: Customize Grouping Menu: Intel VTune Profiler Pane: Call Stack Pane: Options - General Pane: Options - Result Location Pane: Options - Source/Assembly Project Navigator Pane: Timeline Toolbar: Configure Analysis Toolbar: Filter Toolbar: Source/Assembly Toolbar: Intel VTune Profiler Window: Bandwidth - Platform Power Analysis Window: Bottom-up Window: Caller/Callee Window: Cannot Find <file type> File Window: Collection Log Window: Compare Results Window: Configure Analysis Window: Core Wake-ups - Platform Power Analysis Window: Correlate Metrics - Platform Power Analysis Window: CPU C/P States - Platform Power Analysis Window: Debug Window: Event Count - Hardware Events Window: Flame Graph Window: Graphics - GPU Compute/Media Hotspots Window: Graphics C/P States - Platform Power Analysis Window: NC Device States - Platform Power Analysis Window: Platform Window: Platform Power Analysis Window: Sample Count - Hardware Events Window: SC Device States - Platform Power Analysis Window: Summary Window: System Sleep States - Platform Power Analysis Window: Temperature/Thermal Sample - Platform Power Analysis Window: Timer Resolution - Platform Power Analysis Window: Top-down Tree Window: Uncore Event Count - Hardware Events Window: Wakelocks - Platform Power Analysis
Window: Summary x
Window: Summary - Input and Output Summary Window: Summary - Microarchitecture Exploration Window: Summary - GPU Analysis Window: Summary - Hardware Events Window: Summary - Hotspots by CPU Utilization Window: Summary - HPC Performance Characterization Window: Summary - Memory Consumption Window: Summary - Memory Usage Window: Summary - Platform Power Analysis
GPU Metrics Reference x
Average Time Computing Threads Started Computing Threads Started, Threads/sec CPU Time EU 2 FPU Pipelines Active EU Array Active EU Array Idle EU Array Stalled/Idle EU Array Stalled EU IPC Rate EU Send pipeline active EU Threads Occupancy Global GPU EU Array Usage GPU L3 Bound GPU L3 Miss Ratio GPU L3 Misses GPU L3 Misses, Misses/sec GPU Memory Read Bandwidth, GB/sec GPU Memory Texture Read Bandwidth, GB/sec GPU Memory Write Bandwidth, GB/sec GPU Texel Quads Count, Count/sec GPU Utilization Instance Count L3 Sampler Bandwidth, GB/sec L3 Shader Bandwidth, GB/sec LLC Miss Rate due GPU Lookups LLC Miss Ratio due GPU Lookups Local Maximum GPU Utilization Occupancy PS EU Active % PS EU Stall % Ratio to Max Bandwidth, % Ratio to Max Bandwidth, % Ratio to Max Bandwidth, % Render/GPGPU Command Streamer Loaded Samples Blended Samples Killed in PS, pixels Samples Written Sampler Busy Sampler Is Bottleneck Shared Local Memory Read Bandwidth, GB/sec Shared Local Memory Write Bandwidth, GB/sec SIMD Width Size Total, GB/sec Total Time Typed Memory Read Bandwidth, GB/sec Typed Memory Write Bandwidth, GB/sec Typed Reads Coalescence Typed Writes Coalescence Untyped Memory Read Bandwidth, GB/sec Untyped Memory Write Bandwidth, GB/sec Untyped Reads Coalescence Untyped Writes Coalescence VS EU Active VS EU Stall
OpenCL™ Kernel Analysis Metrics Reference x
Computing Task Total Time Instance Count SIMD Width SIMD Utilization Work Size
Energy Analysis Metrics Reference x
Available Core Time C-State D0ix States DRAM Self Refresh Energy Consumed (mJ) Idle Wake-ups P-State S0ix 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
Intel® VTune™ Profiler User Guide

GPU Offload Analysis

Explore code execution on various CPU and GPU cores on your platform, correlate CPU and GPU activity, and identify whether your application is GPU or CPU bound.

Run the GPU Offload analysis for applications that use a Graphics Processing Unit (GPU) for rendering, video processing, and computations with explicit support of SYCL*, Intel® Media SDK and OpenCL™ software technology.

The tool infrastructure automatically aligns clocks across all cores in the entire system so that you can analyze some CPU-based workloads together with GPU-based workloads within a unified time domain.

This analysis enables you to:

  • Identify how effectively your application uses SYCL or OpenCL kernels and explore them further with GPU Compute/Media Hotspots analysis

  • Analyze execution of Intel Media SDK tasks over time (for Linux targets only)

  • Explore GPU usage and analyze a software queue for GPU engines at each moment of time

For the GPU Offload analysis, Intel® VTune™ Profiler instruments your code executing both on CPU and GPU. Depending on your configuration settings, VTune Profiler provides performance metrics that give you an insight into the efficiency of GPU hardware use. You can also identify next steps in your analysis.

Aspects of the GPU Offload Analysis

By default, the GPU Offload analysis enables the GPU Utilization option to explore GPU busyness over time and understand whether your application is CPU or GPU bound. Consequently, if you explore the Timeline view in the Graphics window, you may observe:

  • The GPU is busy most of the time
  • There are small idle gaps between busy intervals
  • The GPU software queue is rarely decreased to zero

If these behaviors exist, you can conclude that your application is GPU bound.

If the gaps between busy intervals are big and the CPU is busy during these gaps, your application is CPU bound.

But such obvious situations are rare and you need a detailed analysis to understand all dependencies. For example, an application may be mistakenly considered GPU bound when the usage of GPU engines is serialized (for example, when GPU engines responsible for video processing and for rendering are loaded in turns). In this case, an ineffective scheduling on the GPU results from the application code running on the CPU.

Configure the Analysis

On Windows systems, to monitor general GPU usage over time, run VTune Profiler as an Administrator.

Run the Analysis

  1. Open the Configure Analysis window. Click the button on the welcome screen (standalone version) or the Configure Analysis(Visual Studio IDE) toolbar button.

  2. Open the Analysis Tree from the HOW pane and select GPU Offload analysis from the Accelerators group.

    The GPU Offload analysis is pre-configured to collect GPU usage data and collect Processor Graphics hardware events (Compute Basic preset).

    NOTE:

    If you have multiple Intel GPUs connected to your system, run the analysis on the GPU of your choice or on all connected devices. For more information, see Analyze Multiple GPUs.

  3. Configure these GPU analysis options:

    • Use the Trace GPU programming APIs option to analyze SYCL, Level-Zero, OpenCL™, and Intel Media SDK programs running on Intel Processor Graphics. This option may affect the performance of your application on the CPU side.

    • Use the Collect host stacks option to analyze call stacks executed on the CPU and identify critical paths. You can also examine the CPU-side stacks for GPU computing tasks to investigate the efficiency of your GPU offload. When results display, sort through SYCL*, Level-Zero, or OpenCL™ runtime call stacks by selecting a Call Stack mode in the filter bar.

    • Use the Analyze CPU-GPU bandwidth option to display data transfers based on hardware events on the timeline. This type of analysis requires Intel sampling drivers to be installed.

    • Use the Show GPU performance insights to get metrics (based on the analysis of Processor Graphics events) that help you estimate the efficiency of hardware usage and learn next steps. The following Insights metrics are collected:

      • The EU Array metric shows the breakdown of GPU core array cycles, where:

        • Active: The normalized sum of all cycles on all cores spent actively executing instructions. Formula:

        • Stalled: The normalized sum of all cycles on all cores spent stalled. At least one thread is loaded, but the core is stalled for some reason. Formula:

        • Idle: The normalized sum of all cycles on all cores when no threads were scheduled on a core. Formula:

      • The EU Threads Occupancy metric shows the normalized sum of all cycles on all cores and thread slots when a slot has a thread scheduled.

      • The Computing Threads Started metric shows the number of threads started across all EUs for compute work.

  4. Click Start to run the analysis.

NOTE:
Families of Intel® Xe graphics products starting with Intel® Arc™ Alchemist (formerly DG2) and newer generations feature GPU architecture terminology that shifts from legacy terms. For more information on the terminology changes and to understand their mapping with legacy content, see GPU Architecture Terminology for Intel® Xe Graphics.

Run from Command Line

Type this command:

$ vtune -collect gpu-offload [-knob <knob_name=knob_option>] -- <target> [target_options]

NOTE:

To generate the command line for any analysis configuration, use the Command Line button at the bottom of the interface.

Once the GPU Offload Analysis completes data collection, the Summary window displays metrics that describe:

  • GPU usage
  • GPU idle time
  • The most active computing tasks that ran on the CPU host
  • The most active computing tasks that ran on the CPU when the GPU was idle
  • The most active computing tasks that ran on the GPU, along with occupancy information


You also see Recommendations and guidance for next steps.

Analyze Multiple GPUs

If you connect multiple Intel GPUs to your system, VTune Profiler identifies all of these adapters in the Target GPU pull down menu. Follow these guidelines:

  • Use the Target GPU pulldown menu to specify the device you want to profile.
  • The Target GPU pulldown menu displays only when VTune Profiler detects multiple GPUs running on the system. The menu then displays the name of each GPU with the bus/device/function (BDF) of its adapter. You can also find this information on your Windows (see Task Manager) or Linux (run lspci) system.
  • If you do not select a GPU, VTune Profiler selects the most recent device family in the list by default.
  • Select All devices to run the analysis on all of the GPUs connected to your system.
  • Full compute set in Characterization mode is not available for multi-adapter/tile analysis.

Once the analysis completes, VTune Profiler displays summary results per GPU including tile information in the Summary window.

Analyze Data Transfer Between Host and Device

To understand the efficiency of data transfer between the CPU host and GPU device, see metrics in the Summary and Graphics windows.

The Summary window displays the total time spent on computing tasks as well as the execution time per task. The difference indicates the amount of time spent on data transfers between host and device. If the execution time is lower than the data transfer time, this indicates that your offload schema could benefit from optimization.

In the Summary window, look for offload cost metrics including Host-to-Device Transfer and Device-to-Host Transfer. These metrics can help you locate unnecessary memory transfers that reduce performance.

In the Graphics window, see the Total Time by Device Operation Type column, which displays the total time for each computation task.



The total time is broken down into:

  • Allocation time
  • Time for data transfer from host to device
  • Execution time
  • Time for data transfer from device to host

This breakdown can help you understand better the balance between data transfer and GPU execution time. The Graphics window also displays in the Transfer Size section, the size of the data transfer between host and device per computation task.

Computation tasks with sub-optimal offload schemas are highlighted in the table with details to help you improve those schemes.



Examine Energy Consumption by your GPU

In Linux environments, when you run the GPU Offload analysis on an Intel® Iris® X e MAX graphics discrete GPU, you can see energy consumption information for the GPU device. To collect this information, make sure you check the Analyze power usage option when you configure the analysis.

NOTE:
Energy consumption metrics do not display in GPU profiling analyses that scan Intel® Iris® X e MAX graphics on Windows machines.

Once the analysis completes, see energy consumption data in these sections of your results.

In the Graphics window, observe the Energy Consumption column in the grid when grouped by Computing Task. Sort this column to identify the GPU kernels that consumed the most energy. You can also see this information mapped in the timeline.

Tune for Power Usage

When you locate individual GPU kernels that consume the most energy, for optimum power efficiency, start by tuning the top energy hotspot.

Tune for Processing Time

If your goal is to optimize GPU processing time, keep a check on energy consumption metrics per kernel to monitor the tradeoff between performance time and power use.

Move the Energy Consumption column next to Total Time to make this comparison easier.

You may notice that the correlation between power use and processing time is not direct. The kernels that compute the fastest may not be the same kernels that consume the least amounts of energy. Check to see if larger values of power usage correspond to longer stalls/wait periods.

Support for SYCL* Applications using oneAPI Level Zero API

This section describes support in the GPU Offload analysis for SYCL applications that run OpenCL or oneAPI Level Zero API in the back end. VTune Profiler supports version 1.0.4 of the oneAPI Level Zero API.

Support Aspect

SYCL application with OpenCL as back end

SYCL application with Level Zero as back end

Operating System

Linux OS

Windows OS

Linux OS

Windows OS

Data collection

VTune Profiler collects and shows GPU computing tasks and the GPU computing queue.

VTune Profiler collects and shows GPU computing tasks and the GPU computing queue.

Data display

VTune Profiler maps the collected GPU HW metrics to specific kernels and displays them on a diagram.

VTune Profiler maps the collected GPU HW metrics to specific kernels and displays them on a diagram.

Display Host side API calls

Yes

Yes

Source Assembler for computing tasks

Yes

Yes

Support for DirectX Applications

This section describes support available in the GPU analysis to trace Microsoft® DirectX* applications running on the CPU host. This support is available in the Launch Application mode only.

Support Aspect DirectX Application

Operating system

Windows OS

API version

DXGI, Direct3D 11, Direct3D 12, Direct3D 11 on 12

Display host side API calls

Yes

Direct Machine Learning (DirectML) API

Yes

Device side computing tasks

No

Source Assembler for computing tasks

No

Parent topic: Accelerators Analysis Group
Level Two Title