About

This repo contains two minimal VSG applications that are minimal repro cases for AMD GPU performance issues on Windows. (Linux performance has not yet been tested)

For a detailed discussion of this issue, see: VulkanSceneGraph Issue #1208

AMD Performance issue:

On Windows with AMD GPUs, the two included apps are showing heavy "Copy" workload in the Windows Task-Manager, and the achieved framerate (FPS) are far below what would be expected from such simple Vulkan apps.

For comparison, an NVidia RTX 2080 Ti running the same applications is showing little to no workload & delivering high FPS:

PS: For the window_perf app, the Windows Task-Manager is additionally showing a 50% 3D workload, on top of the already unexpected 50% Copy workload.

Initial Setup

^{(should only be needed once)}

git submodule update --init --recursive
.\vcpkg\bootstrap-vcpkg.bat
configure.bat

Building the applications

build.bat
OR
cmake --build build --config Release

⚠IMPORTANT: make sure you build the CMake Release config of the apps, the performance problems will be much less obvious in Debug builds!

Running the applications

cd build\Release
offscreen_perf.exe
window_perf.exe

offscreen_perf Command-Line

--debug | -d     enable Vulkan validation layer
--api | -a       enable Vulkan api-dump layer
-n <int>         render the given number of frames and exit the application
-f               write frame-delimiter log messages to console
                 (can be helpful when combined with --api | -a)
--details        print Vulkan function argument details when using api-dump
--logfile        write the Vulkan api-dump output to a vk_api.log file instead of console

window_perf Command-Line

--debug | -d     enable Vulkan validation layer
--api | -a       enable Vulkan api-dump layer
--fullscreen     run app in fullscreen mode