High CPU usage caused by fontd on OS X

Some time ago I realised that the fontd process was chewing up my CPU cores. In my case this seemed to coincide with using the final Presto Opera build (v12.16) but font related issues can be caused by just about any application.

OS X uses the Apple Type Server process, which stores commonly used fonts in a cache for quick access. These files can become corrupted and may affect system performance and stability. So sometimes it may be advisable to do a little maintenance. Here are two simple steps that may help sort font related issues.

Clear the font cache

Clearing the database is done by opening a terminal session and issuing the following command:
sudo atsutil databases -remove; atsutil server -shutdown

Apple Type Server will be restarted immediately by launchd after running the command, so there’s no need to ping the server with
atsutil server -ping

Restart your computer immediately after performing this action.

Validate your fonts

To look for and delete any conflicting fonts, open Font Book, select all your fonts, right click and select “validate fonts” from the context menu. The result will show whether any fonts are giving you grief. You can delete the conflicting fonts but ensure that you don’t delete any required system fonts (which could make your system unstable.)

For more info, make sure you check out Kurt Lang’s very comprehensive article about OS X font management.