Types of Cache Misses | Computer Architecture & Organisation (CAO) - Computer Science Engineering (CSE) PDF Download

Introduction

Types of Cache misses

• Compulsory Miss 
  It is also known as cold start misses or first references misses. These misses occur when the first access to a block happens. Block must be brought into the cache.
• Capacity Miss
  These misses occur when the program working set is much larger than the cache capacity. Since Cache can not contain all blocks needed for program execution, so cache discards these blocks.
• Conflict Miss
  It is also known as collision misses or interference misses. These misses occur when several blocks are mapped to the same set or block frame.These misses occur in the set associative or direct mapped block placement strategies.
• Coherence Miss
  It is also known as Invalidation. These misses occur when other external processors, i.e., I/O updates memory.

Properties of these Cache misses

• Compulsory misses occur same in all types of direct mapped, set associative and associative caches.
• Coherence misses occur same in all types of direct mapped, set associative and associative caches.
• Conflict misses occur high in direct mapped cache, medium in set associative cache, and zero in associative mapped cache.
• Capacity misses occur low in direct mapped cache, medium in set associative cache, and high in associative mapped cache.