YUNOVA · Computer Organisation & Architecture · Module 13: Storage and buses

Secondary storage: HDD and SSD

Notes for offline study · 3 November 2026

Secondary storage: HDD and SSD

Key points

  • HDD access time = seek time + rotational latency + transfer time.
  • Average rotational latency is half a rotation.
  • SSDs have no moving parts, so random access is much faster than on HDDs.