DXVK-NVAPI

Experimental non-complete NVAPI implementation on top of DXVK

This repository provides a basic alternative implementation of the NVAPI extensions for DXVK. It is mostly a direct copy of DXVK-AGS, but adjusted for NVAPI.

This implementation currently forwards the following NVAPI D3D11 features to DXVK:

SetDepthBoundsTest
BeginUAVOverlap/EndUAVOverlap
MultiDrawInstancedIndirect/MultiDrawIndexedInstancedIndirect

It also implements some methods for adapter/display topology and system information.

This implementation has been tested with Unreal Engine 4, mostly the game Assetto Corsa Competizione and several UE4 technology demos. Unreal Engine 4 utilizes SetDepthBoundsTest, it may yield like 1% extra performance which seems to be the norm when Depth bounds test is used.

The 32bits version of this implementation has been briefly tested with the Monster Hunter Official Benchmark where it also yields a similar small gain in performance.

Basic topology and system information (vendor ID, driver version etc) has been tested with GPU Caps Viewer and GPU-Shark. The game Get Even, which seem to verify the driver version during launch, starts fine with this implementation.

Requirements

This implementation is supposed to be used on Linux using Wine or derivates like Proton. It uses several DXVK extension points, having DXVK (D3D11 and DXGI) is a requirements. Using Wine's D3D11 or DXGI will fail. Usage of NVAPI-DXVK is not restricted to NVIDIA-GPU's since no specific NVIDIA hardware features are needed.

How to build

Like DXVK, this library is being built as a Windows DLL using MinGW, and has essentially the same build requirements. Using MinGW versions older than MinGW 7 might fail.

Run:

./package-release.sh master /your/path

Alternatively DXVK-Docker provides a way for a build setup using docker/podman. Pre-built binaries are available at https://github.com/jp7677/dxvk-nvapi/releases.

How to use

Copy nvapi64.dll/nvapi.dll into the system32/syswow64 folder of your x64/x86 Wine prefix.
Make sure that your prefix uses the native version of nvapi64, e.g. with WINEDLLOVERRIDES=nvapi,nvapi64=n.
Disable the nvapiHack in DXVK, see dxvk.conf. Spoof an NVIDIA GPU when running a non-NVIDIA GPU, see dxvk.conf. This needs DXVK's dxgi.dll, use it e.g. with WINEDLLOVERRIDES=dxgi=n.

Debugging

DXVK-NVAPI prints some logging statements to the console. Optionally those statements can be written to a log file using the following environment variable:

DXVK_NVAPI_LOG_PATH Enables file logging and sets the path where the log file dxvk-nvapi.log should be written to. Log statements are appended to an existing file. Please remove this file once in a while to prevent excessive grow.

References and inspirations

Many thanks to the corresponding authors!

liam-middlebrook / dxvk-nvapi