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Replacement Policy

Caches have finite size. When they run out, one block of memory has to be replaced with another (this process is referred to as eviction). Eviction priorities are decided by the cache's replacement policy.

  • Random - A random cache block is evicted
  • Least Recently Used (LRU) - Suffers from an overhead of maintaining last usage time, thus only preferred for smaller caches
  • Psuedo LRU - only tracks least recently used block
  • FIFO - used in caches of high size
  • Not Most Recently Used (NMRU) - any previous strategy, except with the added rule that the most recently used cache block can't be evicted