Force GPU

Force GPU is a portable Linux utility that solves a common multi-NVIDIA headache: games (especially Unity titles and Proton/Steam Play games) often launch on the wrong GPU by default.

On systems with two or more NVIDIA cards (for example, an RTX 3060 + RTX 4060 Ti), many games and engines ignore the “secondary” card unless you explicitly force them. Force GPU detects the GPUs on the machine, lets you pick the one you want from a simple dropdown, remembers your choice, and generates the exact Steam launch options (plus the right environment variables and flags) so the game actually uses that card.

What it does

• Scans available NVIDIA GPUs with nvidia-smi

• GUI to select the target GPU and a profile (Unity, Proton, Native Linux, or Everything)

• One-click “Copy launch options” for Steam

• CLI mode for scripting or direct use

• Saves your preferred GPU so you don’t have to re-select it every time

• Handles the right combination of variables and flags for each engine:

  • Unity: -force-device-index plus PRIME/Vulkan selection

  • Proton/DXVK: device name filtering

  • Native Vulkan/OpenGL: appropriate PRIME and layer settings

Requirements

• NVIDIA proprietary drivers + nvidia-utils

• Python 3

• Optional: python3-tk for the GUI

It’s designed to be dropped into any folder, made executable, and shared as a self-contained tool. Just run it, pick your preferred GPU, copy the launch options into Steam, and verify with nvidia-smi that the game is using the card you chose.

Ideal for dual-NVIDIA Linux desktops where games stubbornly prefer the primary (often weaker) GPU.