15 Mac Settings to Improve Performance Safely: Fix Slow Startup, Storage, CPU, and Memory Issues

The conclusion of these 15 Mac settings to improve performance safely is simple: identify the cause of a slow Mac and change only the related setting. To fix slow startup, storage, CPU, and memory issues, adding a “speed booster” is not the best first move. Check what launches automatically, how much storage is available, and which apps are using CPU and memory.

Even a capable Mac can feel sluggish when several sync tools run in the background or the startup disk has little free space. On the other hand, deleting caches or forcing memory to clear without a diagnosis may accomplish nothing and can put important work at risk.

This guide was checked against Apple’s current documentation on August 1, 2026. It presents 15 built-in Mac settings and checks in a practical order. Make one change at a time, keep a note of the original value, and compare the specific symptom you care about, such as login time, app responsiveness, or sustained fan noise.

First, understand that no single setting speeds up every Mac

Apple lists several possible causes of a slow Mac, including insufficient free space on the startup disk, an app demanding more memory than is readily available, incompatible software, and disk problems. Apple’s guide for what to check when a Mac runs slowly does not describe one universal performance switch.

Treat the following list as a diagnostic sequence, not as 15 switches that everyone should enable. Reversible changes come first. Operations that remove data come later and require a verified backup.

Reduce startup and background load with five checks

1. Check automatic macOS updates

Open System Settings, choose General, then Software Update. Apple’s Software Update settings guide explains the controls for checking, downloading, and installing updates. Updates can include bug fixes, but back up important data and confirm compatibility with critical apps before installing during an important project.

2. Remove unnecessary login items

Go to System Settings, General, then Login Items & Extensions. Under Open at Login, remove apps you do not need every time you sign in. Apple’s login item instructions note that apps, documents, folders, and server connections can all appear here. Removing an item from this list does not uninstall the app.

3. Turn off unnecessary background activity

On the same settings page, review Allow in the Background. Keep services that must sync files, deliver essential notifications, check security, or manage passwords. Disable only software you recognize and no longer need. Turning off an unfamiliar entry can stop a feature you rely on.

4. Disable unused third-party extensions

Login Items & Extensions also contains Finder, network, photo, Spotlight, and other extension categories. Use Apple’s extension settings reference to identify their purpose. Do not disable a required VPN, security filter, or workplace authentication extension without checking with its provider or administrator.

5. Uninstall apps you no longer use through the supported method

Use Launchpad, Finder, or the developer’s uninstaller rather than deleting random support files. Apple’s app removal instructions warn that uninstalling an app does not cancel its subscription and may leave you unable to open documents created with it. Confirm both points before removal.

Recover storage space with five settings and decisions

6. Check available space in Storage settings

Open System Settings, General, then Storage. Review both available capacity and the largest categories. Low startup-disk space is one possible cause Apple identifies, but its troubleshooting page does not promise that one fixed number of free gigabytes will speed up every Mac.

7. Delete or move large files you no longer need

Start with files you can identify: old installers, duplicate videos, completed exports, and downloads you can obtain again. Move archives to suitable external storage if they still matter. Back up photo libraries, work documents, and other irreplaceable data before deleting or relocating them.

8. Use Store in iCloud only when it fits your workflow

Apple’s Storage settings documentation describes an option that can keep recent files on the Mac while storing other data in iCloud as space is needed. It can reduce local storage use, but it requires enough iCloud capacity and a network connection for files that must be downloaded again. It is a poor fit for files that must always remain available offline.

9. Enable Optimize Storage when its listed content is safe to remove locally

Optimize Storage can automatically remove watched Apple TV movies and shows from the Mac while allowing them to be downloaded again. It does not indiscriminately delete every document you created. Read the description presented on your Mac before enabling it because the available recommendations can depend on the services you use.

10. Enable automatic Trash emptying only after confirming backups

This setting deletes items that have remained in the Trash for more than 30 days. Once automatically removed, they cannot be restored through the normal Put Back command. Leave it off if you treat the Trash as temporary storage, and verify Time Machine or another backup before relying on automatic deletion.

Identify CPU and memory pressure with three checks

11. Inspect CPU activity in Activity Monitor

Open Activity Monitor from Applications, Utilities, then select CPU. Apple’s CPU activity guide explains the System, User, and Idle percentages and the per-process view. A brief spike can be normal. Look for a recognized app that remains near the top while you are not asking it to perform intensive work.

12. Check memory pressure rather than chasing free RAM

Select Memory and look at the Memory Pressure graph. Apple’s memory usage guide explains that memory pressure reflects free memory, swap activity, wired memory, and cached files. macOS intentionally uses available RAM for useful work and caching, so a low “free memory” number alone does not prove that the Mac is slow. Note which apps are open if memory pressure stays yellow or red.

13. Quit only an unused or incompatible app you can identify

Save your work first and use the app’s normal Quit command. Force Quit is for an app that no longer responds and can discard unsaved changes. After quitting, repeat the task that felt slow. If the problem returns, check the developer’s compatibility and update information instead of terminating unfamiliar macOS processes.

Match display and power behavior to your needs

14. Reduce motion and transparency, then judge the visual result

In System Settings, Accessibility, enable Reduce Motion. Under Accessibility, Display, you can also enable Reduce Transparency. Apple’s accessibility display reference says these settings reduce interface motion and replace some transparent backgrounds with opaque ones. They may make interaction feel calmer, but Apple does not promise a processing-speed increase on this page. Turn them back off if you prefer the original appearance.

15. Choose an energy mode appropriate for the task on supported Macs

Supported models offer energy modes under System Settings, Battery. Apple’s Mac power mode guide explains that Low Power Mode reduces energy use, while High Power Mode can improve performance for demanding workloads and may allow fans to run faster. High Power Mode is not available on every Mac and can use more energy and create more fan noise. Automatic is a sensible everyday default; compare High Power only for demanding work on a supported model.

If performance does not improve, use Safe Mode and First Aid to narrow the cause

If the 15 checks do not explain the slowdown, stop adding tweaks and isolate the problem. Apple’s Safe Mode instructions describe how Safe Mode can help determine whether software loaded during startup is involved. The steps differ between Apple silicon and Intel Macs, so identify the Mac type and follow the matching official procedure.

For symptoms involving damaged files, unexpected app exits, external-device errors, or startup trouble, back up first and follow Apple’s Disk Utility First Aid instructions. If First Aid fails, the drive makes unusual noises, or the Mac cannot start reliably, avoid repeated experiments and contact Apple Support or a qualified service provider.

Summary

The safest way to improve Mac performance is to identify the load instead of changing every setting. Review login and background items first, then storage, CPU activity, and memory pressure. Treat display effects and energy modes as optional adjustments that depend on your hardware and preferences.

For a useful first step today, write down the current state, remove one login item you can confidently identify as unnecessary, restart, and compare the same task again—the smallest controlled change often reveals more than a dramatic “speed-up” promise.