Slowride is a utility for testing the read speed of block devices for POSIX compliant operating systems with root access to /dev/sd*. You can test the read performance of block devices using a time threshold to diagnose read performance.
Command to read 100mb blocks on the entire device with output of blocks above the threshold of 2 seconds:
sudo ./slowride /dev/sda 100 2000
Source code
https://gitlab.com/demensdeum/slowride