Testing disk speeds on a linux server using hdparm

Getting more info on the throughput of a disk( or partition) on a Linux server, you might want to compare the outcome of this command against another well preforming disk ( or partition) :

xxx:~ # hdparm -tT /dev/hda

/dev/hda:
Timing cached reads: 18296 MB in 2.00 seconds = 9154.93 MB/sec
Timing buffered disk reads: 114 MB in 3.03 seconds = 37.58 MB/sec
xxx:~ #

( The -T means to test the cache system (Memory, CPU and buffer cache). The -t means reading data that is not in the cache. )

I did use this to see a difference in disk preformance of a couple of RAID sets where one was configured as WriteThrough and the other was configured as WriteBack. The Write Back option gave us an enormous preformance boost !