hdparm is a good place to start.
sudo hdparm -Tt /dev/sda
dd will give you information on write speed.
If the drive doesn’t have a file system (and only then), use of=/dev/sda.
Otherwise, mount it on /tmp and write then delete the test output file.
dd if=/dev/zero of=/tmp/output bs=8k count=10k; rm -f /tmp/output