federico@cybertron:~$ sudo hdparm -tT /dev/sdb /dev/sdb: Timing cached reads: 25662 MB in 1.99 seconds = 12879.79 MB/sec Timing buffered disk reads: 1306 MB in 3.00 seconds = 434.77 MB/sec federico@cybertron:~$ sudo hdparm -W /dev/sdb /dev/sdb: write-caching = 1 (on) federico@cybertron:~$ sudo hdparm -W 0 /dev/sdb /dev/sdb: write-caching = 0 (off) federico@cybertron:~$ sudo hdparm -tT /dev/sdb /dev/sdb: Timing cached reads: 25252 MB in 1.99 seconds = 12672.90 MB/sec Timing buffered disk reads: 1080 MB in 3.00 seconds = 359.86 MB/sec federico@cybertron:~$