I wondered where he plucked that figure from, I might have
guessed if it was 60000, mind you I did say somewhere in this
thread, that on average the data you want to read will be at
the other side of the disk, so it is nice to see my 'observation'
is part of an industry standard :O)

Oh, it was he
http://www.pcguide.com/ref/hdd/perf/...Latency-c.html
http://en.tldp.org/HOWTO/Unix-Hardwa.../optimize.html