External drives · Speed, cables and hardware
Why does my external drive keep disconnecting from my Mac?
Short answer: Usually a loose or poor cable, an underpowered hub or a tired port; sometimes the drive. Connect directly with the drive's own cable, try another port and run First Aid. Storage Studio pauses and resumes safely, but fix frequent drop-offs.
The usual causes are physical: a loose or low-quality cable, a hub or dock that can't supply enough power, or a port that's worn. Less often it's the drive itself, or the Mac cutting power to it during sleep.
Work through it:
- Plug directly into the Mac with the drive's own cable.
- Try a different port.
- If it's bus-powered, avoid unpowered hubs.
- Run First Aid on it in Disk Utility.
Storage Studio copes safely with disconnects — moves and transfers pause and resume — but frequent drop-offs are worth fixing, because whatever is open from the drive is interrupted each time.