v0.4.0 - MGPU Bridge, Reworked 2nd Pass and Optimization

Release v0.4.0 of the Neural-coprocessor MGPU Bridge, a ReShade add-on that runs DLSS Neural Rendering on a second GPU while the first renders the game.

New in 0.4.0

Refactors and improvements. Better performance and image stability in games that run DLSS. The gain grows with resolution, so 4K should see the biggest gains. No more trailing after menus and loading screens.

Reworked 2nd pass. Better performance and better utilization of the second card. The old 2nd pass is still there as Full, under Experimental settings.

Pass 1 scale (NRS), by N01950, is a switch under Experimental settings. It reduces the cost of the first pass, as an alternative to an upscaling pass on the neural output.

A safe mode for DcompOverlay=1. If you run into a DWM or driver issue with one display, such as a game that freezes or stops presenting, set DcompSafeMode=3 in mgpu.ini. If that does not fix it, set StartupTrace=1 and send me the log.

Games without DLSS. The first launch finds the right motion vectors faster and more reliably.

Launcher. A new Optimization row on the Options page: NRS, Native upscaling or Experimental upscaling, to compare against Off. Copy files replaces an old mgpu.ini, keeps your Dcomp settings, and can keep a backup.

Upgrading

From 0.3.x: replace the files and take the new mgpu.ini. The launcher's Copy files does it for you and keeps your Dcomp settings.

From 0.2.4 or older: replace the files and take the new mgpu.ini. It sets DX11=1 and DcompOverlay=1, and adds DcompMultiDisplay.

From 0.1.0: move nvngx_dlssnr.dll into an mgpu folder beside the add-on, and delete the copy next to the game's exe.

What's in the zip

Where it goes

Everything goes in the folder with the game's exe:

Game.exe
dxgi.dll                (ReShade, add-on build)
ReShade.ini
ReShadePreset.ini
nvngx.dll_mgpu_bridge.addon64
mgpu.ini
gpu1.ini
ReShade2.ini
mgpu\nvngx_dlssnr.dll   (not in this download)
reshade-shaders\Shaders\mgpu_depth_tap.fx

The mgpu folder is the one step you do by hand.

Do not rename the add-on.

Nothing from NVIDIA is included in this download, and none of it may be.

What you need

• Hardware: two RTX 50-series GPUs. One monitor, on the DLSS 5 GPU; the GPU that renders the game is headless. A contributor reported 40-series working.
• ReShade: 6.8.0 or newer, installed with add-on support.
• Game API: DirectX 12 or DirectX 11. Vulkan does nothing.
• Other add-ons: none alongside it.

Before you run it

Do not change the resolution, the DLSS mode or the DLSS preset while the bridge runs. Change them, then restart the game.

Run the launcher's install check first.

The bridge can take a while to arm, and that is normal.

Low FPS? The GPU that runs DLSS 5, or your PCIe bandwidth, may be too low for 3440x1440 or 3840x2160. Try one of these:

• Render the game on the weaker GPU.
• Turn on Pass 1 scale (NRS) under Experimental settings in the panel, or set NRScale=0.75 and NRScaleResolveDepth=0 in mgpu.ini.
• Turn on Native upscaling.
• Lower the resolution.

Turn off frame generation. It still flickers, and some games crash at start with it on.

Titles this build was run on

Status

Research code, not a finished product. It creates a second D3D12 device and allocates cross-adapter shared heaps.

SmartScreen and antivirus may flag the unsigned DLL and the launcher. I do not pay for a certificate; you can build both from source.

Provenance

Built by this Actions run.

mgpu_bridge_0.4.0.zip           SHA-256: 32516e1bb271da5bdc37918231826618e245774bdfb6ab90aba56ba97eb7ff44
mgpu_bridge_launcher_0.4.0.zip  SHA-256: e1cbc8da14a2a874c44bcb54cb35ea91b16a59c2f625b3c320487fbded7b2a3a

To check a download, run this in PowerShell in the folder with the zip:

Get-FileHash .\mgpu_bridge_0.4.0.zip -Algorithm SHA256
Get-FileHash .\mgpu_bridge_launcher_0.4.0.zip -Algorithm SHA256

Compare the result with the digest above.