You paid €1,500 for it 4 years ago, and today it takes 3 minutes to start? You're not alone. Here are the 6 main causes I see on my clients' Macs in Cluses and Sallanches.
1. Disk is full
macOS needs at least 10% free space. Below that, it slows down, freezes, writes slowly.
Fix: Apple → About This Mac → Storage → Manage.
2. Too many startup apps
Each install adds apps to startup: Spotify, Dropbox, OneDrive, Adobe Creative Cloud, Slack…
Fix: System Settings → General → Login Items → uncheck what you don't need.
3. Spotlight indexes endlessly
If you have many files or a corrupted index, Spotlight re-indexes in a loop.
Fix: System Settings → Siri & Spotlight → Privacy → add your home folder then remove it (forces clean re-index).
4. macOS too old or too new for the hardware
Apple drops support after 7 years on average. Options: OpenCore Legacy Patcher to install Sonoma on a 2014-2017 Mac, or switch to Linux Mint for 5 more years.
5. Worn-out battery (MacBook)
A worn battery automatically reduces performance to preserve runtime.
Check: Apple → About → More Info → System Report → Power → "Cycle Count" and "Condition".
Replacement at my place in Cluses: €80 hardware plan + part (€50-130 depending on model).
6. End-of-life SSD
On 2012-2015 Macs the disk can be replaced. On recent Macs (soldered SSD) it's harder. Diagnostic in 5 min via SMART.
When to replace?
If your Mac is over 8 years old AND the logic board shows warning signs (frequent kernel panics), a refurbished MacBook Air M3 at €700-900 may be more cost-effective.
Mac audit in Cluses: +33 7 83 44 65 99 — on-site diagnosis from €80.