Secondary Storage

• Holds much more data than main memory
• Sometime MUCH MUCH more
• But is much slower
• Hard Drives
  • A series of platters
  • A series of read/write heads
  • A track is a single loop around the disk
  • A sector is a portion of a track
  • A block is data stored on a sector
  • Block size, sector count, tracks, platters and such vary with time
  • Seek time
  • Access Time
  • Latency
  • transfer rate
• Magnetic tape
  • sequential access vs random access
  • Cheep and can be moved off site
  • Backup

Parallel Computers

• UMA/NUMA
• Clusters
• Pipelining
• Flynn