Module 1: Basics and Background
  Lecture 4: Memory and Disk Accesses
 

                                            

 

Typical disk parameters
  • Average seek times from 4-10 ms
  • Rotational speeds are 60, 90, 120, 250 revolutions per second, i.e. ,3600, 5400, 7200, 15000 rpm respectively
  • Sector sizes vary between 512 bytes and 1024 bytes
  • 400 to 1000 sectors per track
  • 20,000 to 50,000 tracks per surface
  • 1 to 5 platters per disk