External drives · Choosing a drive
Are cheap or unbranded external SSDs safe to use?
Short answer: Be wary: some very cheap drives fake their capacity and lose data once they fill, and others use slow, short-lived parts. Buy a reputable brand from a trusted seller, and test a doubtful drive by filling it and checking the files before trusting it.
Be careful. Some very cheap drives report more capacity than they really have — they seem fine until they fill up, then silently lose or corrupt what you copied. Others use slow, low-endurance parts. A reputable brand from a trusted seller is the safer buy for anything that holds your files.
If you already have one:
- Copy a large amount of data onto it — close to its full size — then check that the files open and match the originals.
- Run First Aid in Disk Utility.
- Don't make it the only copy of anything until it has passed.
Storage Studio's speed test checks speed, not true capacity, so a fake-capacity drive can pass it — test the capacity yourself before relying on it.