Some Mac users may find that the mds_stores process is running, consuming unreasonable amounts of CPU and memory when viewed in Activity Monitor. Often this is accompanied by abnormally sluggish performance on the Mac, which is what prompted a visit to Activity Monitor to begin with, and there you can find that mds_stores is taking up 100% or more of the CPU, and perhaps many GBs of RAM to a degree that causes significant changes and visible memory usage.
Let’s dig into mds_stores to learn what it is, what it does, and most importantly for the topic at hand, how to fix it when it’s gone and consuming a large amount of system resources including CPU and memory.
What is mds_stores?
mds_stores is one of the main background processes for the Spotlight search feature and is related to the index database on the Mac. mds_stores will work in the background and catalog files, applications, changes, metadata, media, and file content, so that transparent search results behave as expected and provide faster results.
The mds_stores process always runs in the background on the Mac to keep the Spotlight search database updated, but occasionally it can go haywire and consume an excessive amount of CPU and/or memory, which can cause the Mac to slow down, or physically heat up to the touch.
In the screenshot example here, mds_stores suddenly took 12GB of physical memory, replaced 20GB of virtual memory, took up 100% CPU, and dragged the M series performance down to molasses. It’s annoying, but there is a pretty simple solution.
How to Fix mds_stores Taking Up High CPU and Memory Usage on Mac
First, remember that mds_stores works because it points to a Mac. So it’s best to let that indexing finish, after which the mds_stores process should go back to normal resource usage. If the mds_stores resource usage is excessive and you want to intervene, here’s what to do:
Best Method: Start over
The cleanest way to handle a faulty mds_stores process is to restart the Mac. Restarting works best because it will gracefully exit the process (and associated processes), dump the caches, and then restart the indexing process again once the Mac has restarted successfully.
- Go to menu Apple and select “Restart”
Restarting can be annoying because it can disrupt your workflow, but so can a faulty process that eats up all available system resources and slows down your Mac’s performance.
Oh, and if you haven’t updated your macOS system software in a while, you should do that too. If there is a known performance bug in Spotlight, it will likely be fixed in a software update.
Quick Workaround: Kill the mds_stores Process
If you can’t get it up and running quickly, a temporary process indexing solution can provide you with a quick temporary fix. You can force stop the mds_stores process to end its heavy use of CPU and memory, but be aware that this is a temporary solution because the mds_stores process will eventually restart itself, and often the root problem is not solved so you may feel yourself quickly returning to mds_stores going hayware and slowly consuming more memory.
- In Activity Monitor, search for “mds_stores”, select it, and click the (X) button on the toolbar.
- Confirm that you want to force quit the process, and confirm with an administrator account
- Now go to Finder, finder menu> Finder settings> Advanced> turn “Show file name extensions” OFF and wait a few seconds, then turn it back on again, this trick restarts Spotlight gracefully.
At this point it’s good practice to close whatever you’re currently working on, save any data, exit applications, and restart your Mac anyway. Anytime some process has completely gone haywire and consumed so much RAM that it’s swapping power to disk, or throttling your CPU, usually the real easiest and cleanest solution to that is to restart the Mac.
What not to do: use Terminal to close and open Spotlight, avoid restarting
You’ll find a lot of updated “tips” from non-experts on the Internet that suggest you use Terminal to say incantations and burn incense during a full moon while turning Spotlight off and on again and being directed to a certain directory path, but this almost never solves the problem of Spotlight consuming too much CPU or memory. It may be temporary, similar to the method of killing the mds_stores process described above, but the fix is temporary (if at all), and since many Mac users are not comfortable with Terminal, it can get them into more trouble than they started with. In the end the best thing to do is restart the Mac.
If you want to try to turn off Spotlight and turn it on, you can use this trick to turn off the file extensions and turn them on to restart Spotlight on Mac, which is much kinder and easier to use than going into Terminal and navigating through disk paths, which has a high chance of making things worse for the average user.
Why is this happening?
Spotlight does most of the work on modern Macs, and targeting happens in the background from time to time to keep everything running smoothly. While this often works well and without the user’s notice, sometimes targeting and background tasks go wrong, and whether that’s due to a bug in Spotlight, macOS, third-party app incompatibility, or an idiopathic Spotlight problem altogether, the good news is that fixing the problem is usually pretty straight forward.
Troubleshooting mds_worker and Spotlight can often be annoying, but if you’re a long-time Mac user this probably isn’t your first Rodeo to troubleshoot a Spotlight problem. The truth is that problems with mds and related mds processes have been around forever going back to the early days of Spotlight on Mac, and while it’s an incredibly powerful search engine for Mac that often performs very well, recent versions of Spotlight on macOS with more features seem to be prone to random crashes, crashes, memory leaks, and faulty CPU issues. This isn’t too surprising because Spotlight is no longer just a simple search engine on the Mac, it’s now evolved (probably over-engineered) into a Launchpad replacement, clipboard manager, action launcher, file browser, app launcher, and much more than just a file search engine.
Have you ever had a problem with mds_worker running amuck and consuming too much CPU or memory on your Mac? Did you fix it with a simple reboot, or did you follow another solution that worked for you?