Merge Sort Performance

As we have seen, Merge Sort is O(n · log(n)). Despite requiring extra storage, Merge Sort has a number of advantages:

• 39% fewer comparisons than Quicksort

• Merge Sort is inherently sequential:
  • has good memory locality and cache performance

  • can be done with off-line media such as disk

  • can be parallelized easily: parts of the input array can be sorted independently by separate computers.

• stable

• can efficiently merge in updates to an existing sorted array

• If the highest element in the low sublist is less than the lowest element in the high sublist, the merge can be omitted.