Tool to objectively test performance various external drives on my Mac via USB & Thunderbolt

I would to test the relative performance of various external storage devices:

  • Thumb drive
    • Samsung MUF-256AB/AM FIT Plus 256GB - 300MB/s USB 3.1 Flash Drive (256 gigs)
  • Spinning metal drive
    • Toshiba Canvio Advance 1TB Portable External Hard Drive USB 3.0, Blue (HDTC910XL3AA)
  • NVMe M.2 solid-state storage adapter
    • EXMTE M.2 NVME USB 3.1 Adapter M-Key M.2 NGFF NVME to USB Card High Performance 10 Gbps USB 3.1 Gen 2 Bridge Chip
    • Samsung 970 EVO Plus Series - 250GB PCIe NVMe - M.2 Internal SSD (MZ-V7S250B/AM)

I do not care about free-of-cost or not, I'd be okay with paying a fee.

I understand benchmarking tools are always biased and unrealistic as compared to real-world usage. Nevertheless, I would like to get an objective sense of the reading and writing throughput on these devices. In particular I would like to see if the NMMe M.2 can saturate the USB 3.0 port on my MacBook and the USB 3.1 port on my Mac mini.

Testing on:

  • MacBook Pro (Retina, 15-inch, Late 2013)
  • Mac mini 2018

I found a couple similar Questions (here & here), but they are 7-8 years old. I imagine things may have changed, now in 2019.


Blackmagic Disk Speed Test

If you're interested in read and write speeds there is an app called Black Blackmagic Disk Speed Test available on the App Store. This doesn't have a database to compare with others but can give you actual speeds for your internal and external drive.


AJA System Test is another commonly used tool to benchmark disk performance for the Mac. It offers graphs and a text report of performance instead of just a dial indicating transfer speed like Black Magic.

If you want to test random I/O, which neither AJA or Black Magic do, you can use the tool fio like you can on Linux. You can expect the IOPS to be much higher on an SSD than on a HDD in this case. fio is available from Homebrew