Glossary
WindowServer
The system process that draws your windows and puts them on screen.
What it is
WindowServer composites every window, menu and animation into what you see on your displays. Every app that draws to the screen goes through it.
Its CPU and GPU use follow what is on screen: more windows, more displays, higher resolutions and apps that redraw constantly all add work.
Why it matters
High WindowServer usage is usually a symptom of another app redrawing too often, not a fault in WindowServer itself.
In Activity Monitor
A process named WindowServer in the CPU and Memory tabs.
In iKnowMyMac
Grouped under the macOS row with other system processes. The GPU card shows system GPU use.
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