Why does my gaming mouse tank the frame rate?

Steps

1. Let Steam apply the 26 August 2026 update, which is where the engine change landed.
2. Load the same save and move the mouse the way that used to cost frames.
3. If it is still bad, lower the polling rate in your mouse software as a test, to confirm whether the mouse is the variable at all.
4. If lowering it changes nothing, treat it as ordinary performance and use the developer's published settings advice instead.

Requirements / limits

• The developer states the engine version and the symptom it addresses. No frame-rate numbers, polling-rate thresholds or hardware list is published.
• The general performance advice is separate and older: turn off the retro effect, set graphics detail to LOW, and lower the resolution.
• This does not claim to fix frame-rate loss caused by a very large number of physics objects, which is a different problem with a different cause.

Common mistakes

• Blaming the graphics settings for a stutter that only appears while the mouse is moving.
• Permanently dropping a mouse to 125 Hz before checking whether the update already fixed it.
• Reading launch-week performance advice as current; it predates the engine change by a week.

Still unverified

• At what polling rate did the problem appear?Not verifiedThe changelog names the class of problem, not a threshold. No source publishes a measured comparison.