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External SSD works slower on the Mac mini M1

The SSD - Samsung T7 2GB

A read seed is about 90 MB/s faster on the 7 years old Macbook then new M1 Mac mini.

The test results:

USB-A (max 625 MB/s)

Mac mini M1

ExFAT = W: 344 MB/s R: 326 MB/s

APFS = W: 362 MB/s R: 324 MB/s

MacBook Pro 2015

ExFAT = W: 403 MB/s R: 414 MB/s

APFS = W: 402 MB/s R: 414 MB/s

USB-C (3.1 Gen.2 max 1250 MB/s)

Mac mini M1

exFAT = W: 693 MB/s R: 695 MB/s

APFS = W: 755 MB/s R: 680 MB/s

MacBook Pro 2015 - no USB-C ports

Mac mini, macOS 10.12

Posted on Apr 27, 2021 4:25 AM

Top-ranking reply

a brody

Level 10

84,049 points

Posted on Apr 27, 2021 6:01 AM

USB speeds are a function of all the devices on the bus. When you read the System report in Apple menu -> About This Mac, and select USB, you will see all USB devices separated by bus. Having just one slower device slows down the whole bus to that speed.

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External SSD works slower on the Mac mini M1

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