Optimizing Spotlight for Better Performance

Spotlight can interrupt important work, suck up CPU time, and generally make a nuisance of itself at inconvenient times. The benefits of Spotlight are truly useful, yet it is possible to benefit from it and yet be less annoyed with its interruptions*.

For best performance, exclude backup volumes, any Photoshop or other scratch folder(s), and in most cases your Time Machine volume, unless a very good reason exists for wanting to search them. They can be unexcluded later at any time, e.g. after a backup is done.

Exclude folders or volumes that do not want indexed and searchable by dragging them to Spotlight’s Privacy panel as show below.

The Spotlight process is the obtusely-named “mds” as seen in Activity Monitor.

* Over the years, Apple has taken no action to make Spotlight behavior predictable or controllable. It is a constant nuisance for your author when erasing and testing drives (repetitive exclusion), when backing up, etc.

Exclude backup volumes, scratch volumes, Time Machine volume

Backup 4X too slow?

Spotlight might decide to start indexing the backup (or original) volume while the backup is in progress, causing a huge slowdown in backup speed (doubling or even quadrupling the required time, not to mention sucking up CPU time).

I never want the backup volume indexed by Spotlight — it’s pointless for me.

The solution? Exclude all backup volumes, and remember that after erasing a volume, you’ll have to re-exclude it; Spotlight forgets excluded volumes once it’s erased, even if the name remains the same.

Exclude backup volumes from Spotlight index;
generally confusing to start editing the wrong document (backup instead of original)