Storage benchmark (hard disk or SSD) ? Ways in which you can invoke 'dd' to test the write speed: dd bs=1M count=256 if=/dev/zero of=test dd bs=1M count=256 if=/dev/zero of=test; sync dd bs=1M count=256 if=/dev/zero of=test conv=fdatasync dd bs=1M count=256 if=/dev/zero of=test oflag=dsync