Comment by rini17

Badblocks writes easily compressible patterns and I assume harddrive manufacturers try to compress and deduplicate data, masking any defects. Especially on SSDs and SMR. So I prefer to fill the drive with AES-encrypted data like:

yes | openssl enc -aes-256-cbc -out /dev/test-drive

and then decrypt and grep. It's almost as fast as badblocks.