Timing disk read performance with hdparm

You can benchmark you hard disk performance with hdparm. You need install it first:

apt-get install hdparm

You can perform timings of cache/device reads for benchmark and comparison purposes. For meaningful results, this operation should be repeated 2-3 times on an otherwise inactive system (no other active processes) with at least a couple of megabytes of free memory.

deby:~# hdparm -Tt /dev/sda

/dev/sda:
 Timing cached reads:   858 MB in  2.00 seconds = 428.78 MB/sec
 Timing buffered disk reads:   60 MB in  3.03 seconds =  19.78 MB/sec

This measurement is essentially an indication of the throughput of the processor, cache, and memory of the system under test, as well as how fast the drive can sustain sequential data reads under Linux, without any filesystem overhead. Read more about this tool here.