If your Mac has been crawling lately, you’re not alone. It’s one of the most common reasons people reach out to me. And here’s the thing most people don’t realize: a slow Mac is almost never a hardware problem. You almost certainly don’t need a new computer.

Here’s what’s actually going on — and what to do about it.

1. Your Startup Disk Is Nearly Full

This is the number one cause of Mac slowdowns, and most people have no idea it’s happening.

macOS needs free space on your startup disk to operate. It uses that space for temporary files, swap memory, and general system functions. When you drop below about 10-15% free space, your Mac starts to struggle.

How to check: Go to Apple menu → About This Mac → Storage (or System Settings → General → Storage on newer Macs).

What to do: Delete things you don’t need — Downloads folder, duplicate photos, old applications you never open, large video files. External drives and cloud storage (iCloud, Backblaze) are your best friends here.

A simple storage cleanup is often all it takes to get a noticeably faster Mac.

2. Too Many Apps Running at Startup

Every app that launches when you turn on your Mac takes time to load and uses memory while it’s running — even if you never actually use it.

How to check: System Settings → General → Login Items. You’ll see everything that auto-launches.

What to do: Remove anything you don’t actually need running in the background. Most people are surprised how many apps have snuck onto that list.

3. A Runaway Process Is Eating Your CPU

Sometimes a single app or background process goes haywire and starts consuming all your available processing power. You might not even know it’s open.

How to check: Open Activity Monitor (search for it in Spotlight). Click the CPU column to sort by usage. If anything is sitting at 80-100% CPU and you don’t know what it is, that’s your culprit.

What to do: Select the process and click the X button to quit it. If it’s a legitimate app, restarting it usually fixes the issue. If it keeps happening, that app may need to be reinstalled or removed.

4. You Haven’t Restarted in Weeks (or Months)

Macs are designed to run for a long time without restarting, and that’s great — but memory leaks, background processes, and system buildup can accumulate over time.

What to do: Simply restart your Mac. Shut it down fully, wait 30 seconds, turn it back on. You’d be surprised how often this alone makes a significant difference.

5. Your macOS Is Out of Date

Running an old version of macOS can cause performance issues, especially on newer hardware. Apple frequently releases updates that improve speed, fix bugs, and patch security issues.

How to check: System Settings → General → Software Update.

What to do: Install pending updates. If you’re significantly behind, there may be some planning involved — reach out and I can help you do this without losing anything.

6. You’re Low on RAM (Memory)

This is less common but worth mentioning. If your Mac only has 8GB of RAM and you’re running a browser with 20 tabs, Zoom, Spotify, and three other apps — it will slow down.

How to check: Activity Monitor → Memory tab. Look at the “Memory Pressure” graph at the bottom. Green is fine. Yellow or red means you’re pushing the limits.

What to do: Close apps you’re not using. If you’re consistently in the red, your usage has genuinely outgrown your RAM — at which point a newer Mac may actually make sense.

When to Call Me

If you’ve worked through the list above and your Mac is still slow, or you’re not comfortable digging into Activity Monitor and system settings, this is exactly the kind of thing I handle quickly.

Most slow Mac situations are resolved in a single session — either remote or on-site. I diagnose the real cause, fix it, and make sure you understand what happened so it doesn’t come back.

📱 Text me at (503) 567-9858 or send an email and we’ll get it sorted out.

David Thiele is the founder of Mac a Wish and a former Apple Lead Genius with 22+ years of experience. He provides on-site Mac support throughout the Portland, OR metro area and remote support nationwide.