Your “Options” screen is a great opportunity to educate players about the impact that each graphics setting has on power consumption and carbon emissions, empowering them to make their own decisions and subtly reminding them that everything comes with a cost, while Reducing Electricity Use at Runtime.

It’s now a common practice for PC games to show how much VRAM each graphic option will use so players can tailor their experience to their needs.

Why not show the equivalent, even if just an estimation, in watts per hour or grams of CO₂ emitted according to the player’s local energy mix?

In the PC version of Ultros, we implemented an energy estimate in the Graphics menu, in the shape of an “energy bar” that very roughly estimates the energy use of the game based on the current settings. It doesn’t claim to be exact, but still gives a ballpark impression of which options matter most.

The data model is tiny. We simply ran the game on a dev PC with a power meter attached and compared the watt usage with maximum settings (around 200W) to the minimum (around 90W) and everything in between to get a rough idea of how much each setting contributed to the difference. We chose not to include the watt numbers in the game as they will vary between machines.

We also chose to subtract 80W which is what it took to just run the computer, without the game, so the bar only reflects the energy use of the game itself. From this perspective, running the game in 4K resolution used five times as much additional electricity as running it with the same settings in HD. This also prompted us to add an extra warning label on the 4K option and use HD as the default resolution. As always, resolution and frame rate are by far the biggest factors in energy use.

Hugo Bille