Mac storage basics · External storage and adding space

How can I check how fast my external drive is?

Short answer: System Information shows the speed the drive is connected at; a disk speed test app measures reads and writes. A slow link usually means the cable, port or a hub.

Two quick checks:

  • What it's connected at: open System Information (hold Option and choose the Apple menu → System Information) and look under USB or Thunderbolt for the drive and its link speed.
  • How fast it reads and writes: use a disk speed test app. Storage Studio includes a drive speed test for the drive you set up — see external drives.

If the link speed is lower than expected, try another cable or port and avoid hubs.

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