[root@epd-db root]# hdparm -t /dev/sdb

/dev/sdb:
Timing buffered disk reads: 64 MB in 7.02 seconds = 9.12 MB/sec
[root@epd-db root]# hdparm -t /dev/sdb

/dev/sdb:
Timing buffered disk reads: 64 MB in 2.41 seconds = 26.56 MB/sec
[root@epd-db root]# hdparm -t /dev/sdb

/dev/sdb:
Timing buffered disk reads: 64 MB in 2.02 seconds = 31.68 MB/sec
[root@epd-db root]# hdparm -t /dev/sdb

/dev/sdb:
Timing buffered disk reads: 64 MB in 2.54 seconds = 25.20 MB/sec
[root@epd-db root]# hdparm -t /dev/sdb

/dev/sdb:
Timing buffered disk reads: 64 MB in 2.13 seconds = 30.05 MB/sec
[root@epd-db root]# hdparm -t /dev/sdb