macOS processes › Display and graphics
What is MTLCompilerService on Mac?
MTLCompilerService compiles Metal shaders, the small programs apps and games run on your GPU. You'll see it for a short time when an app first starts, or after an app or macOS update.
What it does
Apps ship shaders in a general form that has to be turned into code for your Mac's exact GPU. MTLCompilerService does that work in a separate process and caches the result so the next launch is faster. Several copies can run when several apps need it.
Why it gets busy
- The first launch of a game or graphics app, or the first launch after it updates.
- After a macOS update, when shader caches often have to be rebuilt.
- Games that compile shaders while you play, which can cause brief stutters.
Why is MTLCompilerService using so much CPU?
High MTLCompilerService CPU means an app is compiling graphics shaders, usually on its first launch or after an update. It's temporary, and the result is cached.
Is it safe to quit?
The app that needed it starts another one, so quitting it only delays the work.
How to calm it down
- On first launch, leave the app at its menu or loading screen for a minute.
- Avoid quitting a game during its shader step, or it starts over next time.
- If it never settles for one app, update or reinstall that app.
In SystemWatch
SystemWatch explains MTLCompilerService in plain language, and History shows that its bursts line up with launching a particular app.
