Performance guide
Slow Mac: find the cause before looking for a cure
A sluggish Mac almost always has an identifiable cause: an app hogging the processor, memory under pressure, a nearly full disk, Spotlight indexing in progress, or a machine that runs hot and throttles itself. The good news: macOS gives you everything you need to diagnose it.
This guide works in order, from most likely to rarest. A warning up front: no software turns a 2017 Mac into a new one, and “RAM cleaners” promising miracles do not do what they claim. The goal is to remove what holds the Mac back, not to believe in magic recipes.
Start with Activity Monitor
Open Activity Monitor: press Cmd + Space and type “Activity”, or go to Applications > Utilities. Keep it open while the Mac is slow.
- CPU tab: sort by % CPU. An app that stays above 80 to 100% for no reason (you are not exporting a video) is suspicious.
- Memory tab: look at the Memory Pressure graph at the bottom rather than the raw numbers.
- Disk tab: heavy, continuous read or write activity often points to indexing, a backup or a sync.
- Energy tab: useful on a laptop to find what drains the battery.
To close a frozen app: select it, click the (x) button in the toolbar, then Quit or Force Quit. Do not force quit system processes you do not recognize.
| Process | What it is | What to do |
|---|---|---|
mds_stores, mdworker | Spotlight indexing | Wait, often a few hours after an update or migration |
High kernel_task | macOS throttling the processor to limit heat | Cool the Mac down, check ventilation |
backupd | Time Machine backup | Let it finish |
photoanalysisd, mediaanalysisd | Photo analysis (faces, objects) | Normal after an import, leave the Mac plugged in |
bird, cloudd, fileproviderd | iCloud Drive and cloud service sync | Wait for syncing to finish |
| Browser renderer processes | Tabs and extensions | Close heavy tabs, review extensions |
Memory: read the pressure, not the “free” memory
macOS deliberately uses almost all available memory: whatever apps do not need serves as a cache to speed things up. “Full” memory is therefore normal. The right indicator is memory pressure:
- green: all is well, even if used memory looks high;
- yellow: macOS is compressing memory and starting to use the disk;
- red: the Mac is genuinely short of memory and writes a lot to disk (see Swap Used). Slowdowns are then inevitable.
If pressure is often yellow or red, the real fixes are to close heavy apps and tabs, replace a resource-hungry app, or accept that an 8 GB Mac is tight for your current workload. Memory on Apple silicon Macs cannot be upgraded.
One-click “RAM cleaners” mostly flush the macOS caches. The free memory counter goes up for a few minutes, then the system has to reload everything, which can even slow things down. It is not a fix for persistently high memory pressure.
Login items and background items
Every app that launches at login and every agent that runs permanently nibbles at memory and processor time. Sort them out:
- Open System Settings > General > Login Items & Extensions (Login Items on macOS Sonoma).
- Under Open at Login, use the − button to remove apps you do not need right at startup.
- Under Allow in the Background, switch off items from apps you no longer use. Switching off a security or backup item may stop it from working: do it knowingly.
- Restart to see the effect.
Leftovers from uninstalled apps sometimes leave agents still running. See uninstalling apps cleanly.
A nearly full disk: the silent slowdown
Below 10 to 15% free space, macOS runs short of room for swap, caches and snapshots. The Mac becomes slow, apps quit unexpectedly and updates refuse to install.
Check in System Settings > General > Storage. If free space is low, that is probably the first thing to fix: follow our method for freeing up disk space.
Spotlight, updates and your browser
Spotlight indexing. After a macOS update, a migration or connecting a large drive, Spotlight reindexes everything. For a few hours, mds_stores keeps the processor and disk busy. Leave the Mac on and plugged in; it sorts itself out. To exclude a large folder or drive from the index: System Settings > Spotlight, then Search Privacy.
Updates. System Settings > General > Software Update. Updates regularly fix memory leaks and performance problems. Update your apps too: an Intel app running through Rosetta on an Apple silicon Mac is slower than its native version.
Browser. It is often the most demanding app on the Mac. Each tab has its own process, and some extensions weigh down every page. In Safari: Safari > Settings > Extensions. In Chrome: the ⋮ > Extensions > Manage Extensions menu, and Window > Task Manager to see each tab’s memory use.
Restart, heat and safe mode
Restart. Many Macs only restart for updates. A restart clears swap, relaunches stuck services and fixes plenty of unexplained slowdowns.
Watch the heat. A Mac that runs too hot lowers its clock speed to protect itself: that is the job of kernel_task. Put a laptop on a hard surface, keep the vents clear and avoid direct sunlight. A MacBook Air has no fan, so it naturally slows down during long computations.
Try safe mode, which starts without third-party items and checks the disk:
- Apple silicon Mac: shut down, press and hold the power button until Loading startup options appears, select the disk, hold Shift and click Continue in Safe Mode.
- Intel Mac: restart while holding Shift until the login window appears.
If the Mac runs smoothly in safe mode, a third-party item is to blame (agent, extension, login app). If it stays slow, consider the hardware: a badly worn battery, an SSD near the end of its life, or simply a Mac that no longer has the power current apps expect.
What MacNeat can do, and what it won’t
MacNeat helps you apply the steps above faster:
- Élan brings together login items, background items (agents and daemons) and targeted maintenance tasks (DNS cache, memory, Spotlight, disk verification).
- Bilan shows your Mac’s health (memory, CPU, disk) and recommendations, for example when memory pressure is high or the startup disk is nearly full.
- Health tracks temperatures, fans, SSD and battery condition, to help spot a hardware cause.
MacNeat also offers a memory release task. To be frank: its effect is temporary, for the reasons explained above. It does not replace more memory or closing apps that use too much. All deletions go through the Trash and operations can be undone.