On Linux I would usually use "hdparm -tT device" when I want a quick idea of how an hard drive is performing compared to another; having switched to Mac OS X a few months back I have yet to find something similar and as easy to use.
I have read that diskutil can do similar things on Mac but I am not clear about how I should use it to do something similar to the hdparm command above.
Any ideas on how to do this or on alternatives? Thanks!
Using file copy in general and dd in particular isn't the great way to measure I/O performance. This is a very good wrap up about WHY it's so.
Microsoft DiskSPD (There's a Linux port for sure!) and a cross-platform FIO (Which is probably recommended...) should be used instead.
https://github.com/microsoft/diskspd/actions
https://github.com/microsoft/diskspd-for-linux
Here's some HOWTO guides on using both DiskSDP and FIO. Windows, Linux, and MacOS X accordingly.
https://learn.microsoft.com/en-us/azure/virtual-machines/disks-benchmarks
https://docs.oracle.com/en-us/iaas/Content/Block/References/samplefiocommandslinux.htm
https://www.nivas.hr/blog/2017/09/19/measuring-disk-io-performance-macos/
I have yet to find an equivalent for hdparm on macOS.
Someone mentioned using dd to get at least a basic idea with a command that is available, which is a little bit helpful. They admitted to not knowing the macOS command line, so here is a Mac specific version:
dd if=/dev/disk0s1 of=/dev/zero bs=4096 count=10240
This will report a very basic bytes per second.
(bear in mind I never used Mac CLI so there can be little differences from what I write)
you could try dd:
dd if=/dev/sda of=/dev/zero bs=4096 count=10240 iflag=direct
This will copy 40MiB of data from the beginning of the drive and show you the average speed.
