Difference Between Internal and External Fragmentation
Internal Fragmentation | External Fragmentation | |
---|---|---|
Cause | Occurs when allocated memory blocks have unused space within them due to allocation techniques or fixed-size partitions | Occurs when free memory is available, but it is scattered in small, non-contiguous blocks |
Location | Exists within allocated memory blocks | Exists between allocated memory blocks or in the free memory pool |
Impact | Reduces memory utilization efficiency | Limits the allocation of large contiguous memory blocks, leading to wastage of memory |
Memory Usage | Actual memory usage is less than the allocated memory | Free memory exists but is fragmented and cannot be used efficiently |
Resolution | Memory compaction or dynamic memory allocation techniques can help reduce internal fragmentation | Compaction or memory relocation techniques may be used to reduce external fragmentation and reclaim scattered free memory |
Examples | Allocating fixed-size memory blocks larger than required by the process | Multiple processes allocated and deallocated memory over time, resulting in scattered free memory blocks |
Common Scenarios | Fixed-size partitioning, paging systems | Dynamic memory allocation, file systems with varying block sizes |
These differences highlight the causes, locations, impacts, and resolution strategies for internal and external fragmentation. Understanding these concepts helps in effectively managing memory utilization and optimizing system performance.