Prerequisite
You are recommended to get familiar how to use Graphics Performance Analyzer - System Analyzer first. System Analyzer is the central interface to record the trace logs for Platform Analyzer. You can refer this link to getting started with System Analyzer. Graphics Performance Analyzer is part of Intel System Studio.
Introduction
Platform Analyzer provides offline performance analysis capability† by reviewing the tasks timelines among real hardware engine, software queue for GPU scheduler and background threads activities. With this utility, developers can quickly review which GPU engines (Render, Video Enhance - Video Processing or Video Codec) resource are involved in the target test application. For example, the trace result can reveal whether the Gen graphics HW codec acceleration is used or not. Platform Analyzer can also provide a rough clue regarding performance issue by reviewing tasks timelines.
Take a quick look about Platform Analyzer below. Top window shows when graphics related tasks occurs on hardware engines, GPU software queue and threads timelines. Bottom windows contains overall time cost for each type task and HW engines usage utilization.
†Platform analyzer is part of GPA (Graphics Performance Analyzer) which focuses more on graphics application optimization usage, mainly on Windows DirectX and Android/Linux OpenGL apps. Check the GPA product page to get the quick overview of GPA.
A quick start to capture the trace logs
Follow the normal steps to start analyzing the target application. In windows, it allows to using a hotkeys combination to capture the platform analyzer trace logs directly.
- Right click the “GPA monitors” system icon and choose “Analyze Application” to lunch target application.
- Press Shift + Ctrl + T to capture the trace logs
- Once you see one overlay indicates capture completed as the figure below, the trace logs have been successfully captured.
Find the pattern: what symptom will the performance issues show in Platform Analyzer?
First of all, you might want to understand a little bit about VSYNC and Present function call in Platform Analyzer. Vsync indicates a hardware signal right after that system will output one frame to display device. The interval between two Vsync signals implies the refresh rate of display device. As for Present API, it’s used to indicate the operation to copy/move one frame to another memory destination of frame.
With the background knowledge above, you may watch and investigate these symptoms indicated by Platform Analyzer.
- Irregular VSYNC pattern. (VSYNC intervals should be consistent otherwise screen blinking or flashing symptom may reveal during the test.)
- Long delay (big packet) in GPU engine. (this packet could be the Present call, if the packet size/length in timeline cross multiple VSYNCs, it can cause display frames stuck)
- Overloading - multiple heavy stacked packets in software queue, like the figure below. (Stacked packets means several tasks are schedule in the same time, the packet should be dropped or delayed to process if GPU cannot handle several tasks in timely manner. It also causes display frames stuck)
Further information
Intel System Studio includes three components of GPA, System Analyzer, Platform Analyzer and Frame Analyzer. System Analyzer provides an interface to record the logs what Platform Analyzer and Frame Analyzer need for offline analysis.
GPA Analyzers Name | Functionalities |
System Analyzer | Provide real-time system & app analysis. Central interface to record logs for other GPA analyzers. More information. |
Platform Analyzer | Provide GPU engines and threads activities interactions analysis. Present the captured log by showing all graphics hardware engines workloads (including decoding, video processing, rendering and computing) and threads activities in a timeline view. More information. |
Frame Analyzer | Provide offline single frame rendering analysis. Reconstruct the frame by replaying DirectX/OpenGL APIs logged by System Analyzer. More information |
See also
Intel® Graphics Performance Analyzers (Intel® GPA) Documentation
Register and Download Intel System Studio Windows Professional Edition.