PerfSDK Plugin

NVIDIA Nsight PerfSDK integration for the Flax Editor GPU Profiler. Click a GPU profiler timeline bar or table row to open live chip counter metrics.

Requirements

• Windows x64
• Flax 1.13+
• NVIDIA GPU + Nsight Perf SDK installed
• Environment variable NVPERF_SDK_PATH pointing at your Perf SDK root (e.g. C:\Downloads\PerfSDK_2025_5)

Setup

1. Set NVPERF_SDK_PATH in your user/system environment.
2. Clone plugin via Editor Plugin Window tool, ensure game project references it:

...
"References": [
    {
        "Name": "$(EnginePath)/Flax.flaxproj"
    },
    {
        "Name": "$(ProjectPath)/Plugins/PerfSDK/PerfSDK.flaxproj"
    }
]

2. Open the project and Build & Run (or compile scripts) so the PerfSDK plugin native module links against NVPerf.
3. Play the scene, open Profiler → GPU, enable live recording, then left-click a region.

Supported Platforms

Platforms:

• Windows x64

Graphics APIs:

• DirectX 11
• DirectX 12
• Vulkan

API

In order to access PErfSDK API in C++/C# scripting import it in your code module (modify Game.Build.cs file):

public override void Setup(BuildOptions options)
{
    base.Setup(options);

    // Adds PerfSDF module to PrivateDependencies if supported on current platform (eg. Windows x64)
    PerfSDF.ConditionalImport(options, options.PrivateDependencies);
}

Architecture

Layer	Location
Native NVPerf + HUD	Plugins/PerfSDK/Source/PerfSDK/*.cpp (plugin DLL)
Metrics editor window	Plugins/PerfSDK/Source/PerfSDK/PerfSdkMetricsWindow.cs
Editor plugin wiring	Plugins/PerfSDK/Source/PerfSDK/PerfSDK.cs, GpuProfilerBridge.cs
GPU frame sampling hooks	PerfSDK.cpp via RenderTask delegates (no game C++)
Profiler click plumbing	Engine GpuProfilerRegionCallbacks + Timeline / GPU.cs

gearsDLSS game code has zero PerfSDK C++. All native code lives in the plugin.

The engine does not define COMPILE_WITH_RENDER_PERF or link NVPerf. Only the plugin does when NVPERF_SDK_PATH is set at build time.

Vulkan note

PerfSDK needs extra Vulkan device extensions (VK_EXT_buffer_device_address, VK_KHR_device_group, plus NVPerf profiler extensions). The engine enables these at device creation when NVPERF_SDK_PATH is set before starting the editor.

1. Set NVPERF_SDK_PATH (and VULKAN_SDK for plugin builds).
2. Fully close and reopen Flax Editor so Vulkan device creation picks up the extensions.
3. Rebuild the engine (after engine changes) and Recompile Scripts.