Mac running slow

In short: A Mac that's slowed down over time is usually one of four things: a near-full or failing storage drive, insufficient RAM for what you're doing, a software process eating CPU, or thermal throttling from a dusty cooling system. We diagnose which and fix accordingly.

What’s happening

Slowness on a Mac generally tracks back to one of these:

1. Storage drive nearly full or failing. macOS needs free space to run. Below about 10-15% free, performance drops noticeably. A failing drive (even an SSD) shows up as long waits during reads and writes.
2. Not enough RAM for current workload. Heavy Chrome use, video editing, big files in Photos — RAM pressure forces macOS to swap to disk, which is slower.
3. Background process consuming CPU. Spotlight reindexing, Time Machine running, a misbehaving app, or in some cases malware.
4. Thermal throttling. Dust in the cooling system means the CPU runs hot, which makes macOS slow it down to protect itself.

What to do first

1. Activity Monitor → CPU tab. Sort by % CPU. If something’s at 100%+ and you don’t recognise it, that’s a clue.
2. Apple menu → About This Mac → Storage. If you’re below 15% free, that’s contributing. Move files off or clean up.
3. Memory tab in Activity Monitor. Look at “Memory Pressure”. Red or yellow = you need more RAM (or fewer apps open).

What we do

Workshop diagnostic looks at all four causes:

• Storage health (SMART data, drive speed test, SSD wear levels)
• RAM diagnostic (capacity vs workload)
• Process audit (what’s actually running, what shouldn’t be)
• Thermal inspection (dust, paste condition, fan health)

We give you a written summary of what’s actually causing the slowdown and what would fix it. Often it’s storage upgrade (SSD if not already, or larger SSD) plus a thermal clean. RAM upgrades where the model supports them.

How we quote

The right fix for “slow Mac” varies (SSD upgrade, thermal clean, RAM upgrade, or sometimes just a software cleanup), so we don’t publish a fixed figure. The £75 diagnostic fee covers proper assessment of what’s actually causing it, then we provide a written quote covering parts and labour. Diagnostic fee deducted from any repair you go ahead with.