This sample demonstrates the usage of the new NvAPI interface to synchronize present calls between windows on the same system as well as on distributed systems. It can also be used to check if systems are configured to support synchronized present through DirectX 12 present barrier. A general overview of the interface can be found on the NVIDIA developer blog.
- NVIDIA RTX / Quadro series card (GeForce is NOT supported)
- 472.12 driver or newer
- NVAPI R470 or newer (can be downloaded from here)
The app draws a couple of moving bars and lines to visually check the synchronization quality. In the upper left corner a window with present barrier statistics is shown. There are several keyboard shortcuts that can be used at runtime.
- V - Toggle vsync
- S - Toggle scrolling of the lines
- T - Toggle present barrier
- Q - Toggle usage of the Quadro Sync frame counter
- W - Increase sleep interval between presets by 1ms
- Alt + W - Reset sleep interval between presents to zero (effectively disabling it)
- Shift + W - Decrease sleep interval between presents by 1ms
- 2 - Toggle stereoscopic rendering
A bar at the top of the window indicates the present barrier status.
- red - The swap chain is not in present barrier sync
- yellow - The swap chain is in present barrier sync with other clients on the local system
- green - The swap chain is in present barrier sync across systems through framelock
Clone https://github.com/nvpro-samples/nvpro_core.git
next to this repository (or pull latest master if you already have it):
mkdir build && cd build && cmake .. # Or use CMake GUI
If there are missing dependencies (e.g. glfw), run git submodule update --init --recursive --checkout --force in the nvpro_core
repository.
Then start the generated .sln in VS or run make -j.
Run dx12_present_barrier or ../../bin_x64/Release/dx12_present_barrier.exe
You are advised not to run the debug build unless you have the required validation layers.
Copyright 2022 NVIDIA CORPORATION. Released under Apache License, Version 2.0. See "LICENSE" file for details.