Do application leftovers have any impact on performance?

Apparently, uninstalling an app by dragging it to the bin may leave application leftovers in some folders (such as Library/Preferences/, Library/Applications Support/, Library/StartupItems/ etc...). Several sites explain how removing such leftovers can increase disk space.

However, I have no problem with storage. So, this is my question: apart from taking up disk space, do these application leftovers have any negative impact on performance?

Solution 1:

Application preferences and caches will not have any impact on system performance, but if there are leftover startup daemons running, etc., there could absolutely be a performance penalty. There is no way to know for certain how much of an impact there could be. The best advice I can offer is to always check the application developer's uninstall guidelines. Some applications utilize uninstaller applications to ensure all the application support files are removed.

Solution 2:

Files in the following subfolders of the root level /Library or User Library will not affect the performance of your Mac at all, as they will not be read or executed:

• Application Support
• Caches
• Containers
• Preferences

(Not an exhaustive list.)

Files in the following subfolders might affect performance as they may be loading or trying to load non-existent files:

• StartupItems
• Extensions
• LaunchAgents
• LaunchDaemons

(Again, not an exhaustive list.)