so I'm waiting for two 18TB recertified drives to arrive soon which I want to check for badblocks before using them. I would like to speed things up and test both drives simultaneously.
today I started a testrun with 2 older 500GB drives I still have
Internal - WD Green 3.5" 500 GB 5400/min SATA 3Gb/s @ SATA2 3GB/s
External -WD Elements 2.5" 500 GB 5400/min USB 2.0 @ USB 3.0
both drives are neither empty nor full. The WD Green is NTFS formatted, while the Elements is ext4.
I booted up a linux live distro, checked GParted to check which dev/sd* to choose so I know I am selecting the correct drives.
then I started 2 terminal windows and started
sudo badblocks -s -v -n -f /dev/sdX
with the X standing for the corresponding drive. both jobs started approximately just seconds from one another and are currently running.
what is interesting is, that the external WD Elements USB2.0 seems to be double as fast as the WD Green SATA2. Is that normal? Has this something to do with the filesystem?
when I'm reading the specs correctly, SATA2 should be faster than USB2.0 no?
I will connect my new recertified drives to two SATA3 6Gb/s and will use badblocks -w (for destructive read/write) but can I expect same speeds on both drives?
Or am I doing something wrong here entirely and Linux cannot divide CPU/RAM and other resources evenly between two terminal instances by default? I maybe one badblocks process slowing the other one down?