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Performance Ilist Sorting Performance

github-actions[bot] edited this page Apr 21, 2026 · 9 revisions

IList Sorting Performance Benchmarks

Unity Helpers ships several custom sorting algorithms for IList<T> that cover different trade-offs between adaptability, allocation patterns, and stability. This page gathers context and benchmark snapshots so you can choose the right algorithm for your workload and compare results across operating systems.

Algorithm Cheatsheet

Algorithm Stable? Best For Reference
Ghost Sort No Mixed workloads that benefit from adaptive gap sorting and few allocations Upstream project by Will Stafford Parsons (public repository currently offline)
Meteor Sort No Almost-sorted data where gap shrinking beats plain insertion sort Upstream project by Will Stafford Parsons (public repository currently offline)
Pattern-Defeating QuickSort No General-purpose quicksort with protections against worst-case inputs pdqsort by Orson Peters
Grail Sort Yes Large datasets where stability + low allocations matter GrailSort
Power Sort Yes Partially ordered data that benefits from adaptive run detection PowerSort (Munro & Wild)
Tim Sort Yes General-purpose stable sorting with abundant natural runs Wikipedia - Timsort
Jesse Sort No Data with long runs or duplicates where dual patience piles shine JesseSort
Green Sort Yes Sustainable stable merges that trim ordered prefixes greeNsort
Ska Sort No Branch-friendly partitioning on large unstable datasets Ska Sort
Ipn Sort No In-place adaptive quicksort scenarios needing robust pivots ipnsort write-up
Smooth Sort No Weak-heap hybrid that approaches O(n) for presorted data Smoothsort - Wikipedia
Block Merge Sort Yes Stable merges with √n buffer (WikiSort style) WikiSort
IPS⁴o Sort No Cache-aware samplesort with multiway partitioning IPS⁴o paper
Power Sort Plus Yes Enhanced run-priority merges inspired by Wild & Nebel PowerSort paper
Glide Sort Yes Stable galloping merges from the Rust glidesort research sort-research-rs
Flux Sort No Dual-pivot quicksort tuned for modern CPUs sort-research-rs
Insertion Sort Yes Tiny or nearly sorted collections where O(n²) is acceptable Wikipedia - Insertion sort

What does “stable” mean? Stable sorting algorithms preserve the relative order of elements that compare as equal. This matters when items carry secondary keys (e.g., sorting people by last name but keeping first-name order deterministic). Unstable algorithms can reshuffle equal entries, which is usually fine for numeric keys but can break deterministic pipelines.

Heads up: The original Ghost Sort repository was formerly hosted on GitHub under wstaffordp/ghostsort, but it currently returns 404. The Unity Helpers implementation remains based on that source; we will relink if/when an official mirror returns.

Dataset Scenarios

  • Sorted – ascending integers, verifying best-case behavior.
  • Nearly Sorted (2% swaps) – deterministic neighbor swaps introduce light disorder to expose adaptive optimizations.
  • Shuffled (deterministic) – Fisher–Yates shuffle using a fixed seed for reproducibility across runs and machines.

Each benchmark sorts a fresh copy of the dataset once and reports wall-clock duration. If a cell still shows pending, re-run the benchmark suite to collect fresh data for that algorithm/dataset size.

Run the IListSortingPerformanceTests.Benchmark test inside Unity’s Test Runner to refresh the tables below. Results automatically land in the section that matches the current operating system.

Windows (Editor/Player)

Last updated 2026-04-21 03:15 UTC on Windows 11 (10.0.26200) 64bit

Times are single-pass measurements in milliseconds (lower is better). n/a indicates the algorithm was skipped for the dataset size.

Sorted

List Size Ghost Meteor Pattern-Defeating QuickSort Grail Power Insertion Tim Jesse Green Ska Ipn Smooth Block IPS4o Power+ Glide Flux
100 0.005 ms 0.002 ms 0.001 ms 0.001 ms 0.001 ms 0.001 ms 0.001 ms 0.098 ms 0.001 ms 0.006 ms 0.001 ms 0.002 ms 0.001 ms 0.001 ms 0.001 ms 0.001 ms 0.002 ms
1,000 0.022 ms 0.026 ms 0.007 ms 0.007 ms 0.005 ms 0.006 ms 0.005 ms 1.23 ms 0.006 ms 0.098 ms 0.007 ms 0.017 ms 0.005 ms 0.036 ms 0.005 ms 0.005 ms 0.028 ms
10,000 0.276 ms 0.376 ms 0.071 ms 0.062 ms 0.044 ms 0.056 ms 0.042 ms 14.6 ms 0.062 ms 1.46 ms 0.072 ms 0.168 ms 0.048 ms 0.585 ms 0.044 ms 0.044 ms 0.404 ms
100,000 3.36 ms 4.94 ms 0.717 ms 0.621 ms 0.430 ms n/a 0.415 ms 186 ms 0.609 ms 18.1 ms 0.745 ms 1.67 ms 0.490 ms 7.01 ms 0.429 ms 0.422 ms 4.75 ms

Nearly Sorted (2% swaps)

List Size Ghost Meteor Pattern-Defeating QuickSort Grail Power Insertion Tim Jesse Green Ska Ipn Smooth Block IPS4o Power+ Glide Flux
100 0.001 ms 0.002 ms 0.002 ms 0.001 ms 0.002 ms 0.001 ms 0.001 ms 0.093 ms 0.001 ms 0.006 ms 0.002 ms 0.002 ms 0.001 ms 0.002 ms 0.003 ms 0.002 ms 0.002 ms
1,000 0.022 ms 0.026 ms 0.031 ms 0.007 ms 0.016 ms 0.006 ms 0.014 ms 1.21 ms 0.007 ms 0.098 ms 0.027 ms 0.017 ms 0.006 ms 0.043 ms 0.023 ms 0.015 ms 0.029 ms
10,000 0.277 ms 0.375 ms 0.409 ms 0.071 ms 0.226 ms 0.064 ms 0.167 ms 14.2 ms 0.068 ms 1.41 ms 0.386 ms 0.174 ms 0.069 ms 0.646 ms 0.370 ms 0.160 ms 0.380 ms
100,000 3.33 ms 4.90 ms 4.95 ms 0.710 ms 3.58 ms n/a 2.38 ms 173 ms 0.695 ms 18.1 ms 4.63 ms 1.72 ms 0.603 ms 7.97 ms 5.34 ms 2.24 ms 4.84 ms

Shuffled (deterministic)

List Size Ghost Meteor Pattern-Defeating QuickSort Grail Power Insertion Tim Jesse Green Ska Ipn Smooth Block IPS4o Power+ Glide Flux
100 0.008 ms 0.007 ms 0.005 ms 0.006 ms 0.007 ms 0.016 ms 0.010 ms 0.041 ms 0.007 ms 0.008 ms 0.007 ms 0.010 ms 0.005 ms 0.005 ms 0.023 ms 0.011 ms 0.006 ms
1,000 0.146 ms 0.126 ms 0.093 ms 0.102 ms 0.108 ms 1.38 ms 0.139 ms 0.439 ms 0.106 ms 0.130 ms 0.094 ms 0.186 ms 0.086 ms 0.106 ms 0.422 ms 0.150 ms 0.098 ms
10,000 2.04 ms 1.83 ms 1.19 ms 1.39 ms 1.46 ms 137 ms 1.54 ms 5.42 ms 1.35 ms 1.77 ms 1.28 ms 2.63 ms 1.17 ms 1.52 ms 5.89 ms 1.72 ms 1.41 ms
100,000 29.4 ms 24.5 ms 15.0 ms 17.6 ms 18.0 ms n/a 19.8 ms 68.4 ms 17.5 ms 22.5 ms 15.6 ms 33.6 ms 14.7 ms 20.0 ms 74.4 ms 22.6 ms 17.5 ms

macOS

Pending — run the IList sorting benchmark suite on macOS to capture results.

Linux

Pending — run the IList sorting benchmark suite on Linux to capture results.

Other Platforms

Pending — run the IList sorting benchmark suite on the target platform to capture results.

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