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Storage

Memory (main memory) consists of
  • very large random-addressable array of bytes
  • can fetch single bytes into CPU registers
  • can fetch multi-byte chunks into CPU (e.g. 4-byte int)
  • typically: access time 0.1 µs, size 64 GB
Disk storage consist of
  • very very large block-oriented storage
  • often on spinning disk, fetching 512B-4KB per request
  • typically: access time 30 ms, size 8 TB
  • nowadays, SSD: access time 100 µs, size 1GB