Entity-Component-System Benchmarks

Simple Benchmarks of common ECS (Entity-Component-System) Frameworks:

• EntityX
• EnTT
• flecs
• Ginseng
• mustache
• OpenEcs

TL;DR Results

Update systems (3 systems with mixed entities)

(lower is better)

This is a very little Benchmark with three simple components and three small systems. In wild Entity-Component-Systems can have hundreds of components and a lot of systems and even more complex systems. So always benchmarks YOUR special cases and systems, when needed and compare.

Some frameworks are faster in adding/removing components, others in creating or destroying entities, it always depends on what you need the most. Always choose an ECS-Framework by features, for example EnTT has some great features like a resource-management or events, flecs has some nice add-ons and EntityX has a build-in world/system-manager.

Pick and evaluate a framework you like and have a look at the examples and API design.

Details

Features

All benchmarks are located in benchmark/benchmarks/ and are written with google/benchmark. Each benchmark must implement the template ECSBenchmark.h.

Each framework has a sub-project in src/ and must implement certain features (see src/base).

Components

1. PositionComponent with x and y coord.
2. VelocityComponent with x and y for movement.
3. DataComponent with some nonsense data.

Systems

1. MovementSystem: updates PositionComponent with (const) VelocityComponent
2. DataSystem: updates DataComponent with nonsense
3. MoreComplexSystem: updates Components with random data and nonsense

More Benchmarks

Benchmarks of more common features, like "Creating entities", "Add and remove components", etc.

Features tested

• Create Entities
• Destroy Entities
• Get Component(s)
• Remove and add component
• Systems (for-each entities)

Environment

• OS: Windows 10
• CPU: i7 - 2.8GHz @ 8Cores
• RAM: 16 GB
• Compiler: MSVC (Visual Studio 2019)

Run on my Laptop :)

Create entities

(lower is better)

Destroy entities

(lower is better)

Get one (non-const) component from Entity

(lower is better)

Note:

• Get one non-const component
  1. PositionComponent

Get one (const) component from Entity

(lower is better)

Note:

• Get one const component
  1. const PositionComponent

Get two components from entity

(lower is better)

Note:

• Get non-const- and const-component
  1. PositionComponent
  2. const VelocityComponent

Get three components from entity

(lower is better)

Note:

• Not every entity has three components, some has only two
• Get two non-const- and const-component(s)
  1. PositionComponent
  2. const VelocityComponent
  3. DataComponent (optional)

Remove and add component

(lower is better)

Note:

• Remove and add PositionComponent

Update systems (for-each entities in 2 systems)

(lower is better)

Note:

• Systems used
  1. MovementSystem
  2. DataSystem

Update systems (for-each entities (with mixed components) in 2 systems)

(lower is better)

Note:

• Systems used
  1. MovementSystem
  2. DataSystem
• Not every entity has all three components, some got removed

Update systems (for-each entities in 3 systems)

(lower is better)

Note:

• Systems used
  1. MovementSystem
  2. DataSystem
  3. MoreComplexSystem
• * EnTT iterate components via views
• ** EnTT iterate components via runtime views
• *** EnTT iterate components via groups:
  1. DataSystem: No Group, use registry.view<DataComponent>. (Can't group a single component)
  2. MovementSystem: Partial-owning group, registry.group<PositionComponent>(entt::get<const VelocityComponent>)
  3. MoreComplexSystem: Full-owning group, registry.group<PositionComponent, VelocityComponent, DataComponent>()
• **** EnTT iterate components via view and uses a stable component (StablePositionComponent)

Update systems (for-each entities (with mixed components) in 3 systems)

(lower is better)

Note:

• Systems used
  1. MovementSystem
  2. DataSystem
  3. MoreComplexSystem
• Not every entity has all three components, some got removed
• * EnTT iterate components via views
• ** EnTT iterate components via runtime views
• *** EnTT iterate components via groups:
  1. DataSystem: No Group, use registry.view<DataComponent>. (Can't group a single component)
  2. MovementSystem: Partial-owning group, registry.group<PositionComponent>(entt::get<const VelocityComponent>)
  3. MoreComplexSystem: Full-owning group, registry.group<PositionComponent, VelocityComponent, DataComponent>()
• **** EnTT iterate components via view and uses a stable component (StablePositionComponent)

Iterate over entities with one component

(lower is better)

Notes:

• pre create views/query when possible
• * EnTT uses registry.view and a stable component (StablePositionComponent)
• ** flecs queries

Iterate over entities with two components

(lower is better)

Notes:

• pre create views/query when possible
• * EnTT Full-owning group, registry.group<PositionComponent, VelocityComponent>()
• ** EnTT Non-owning group, registry.group(entt::get<<PositionComponent, VelocityComponent>>)
• *** EnTT Partial-owning group, registry.group<PositionComponent>(entt::get<VelocityComponent>)
• **** EnTT uses registry.view and a stable component (StablePositionComponent)
• ***** flecs Frameworks, iterate components via queries

Iterate over entities with three components

(lower is better)

Notes:

• Not every entity has all three components, some got removed
• pre create views/query when possible
• * EnTT Full-owning group, registry.group<PositionComponent, VelocityComponent, DataComponent>()
• ** EnTT Non-owning group, registry.group(entt::get<<PositionComponent, VelocityComponent, DataComponent>>)
• *** EnTT Partial-owning group, registry.group<PositionComponent, VelocityComponent>(entt::get<DataComponent>)
• **** EnTT uses registry.view and a stable component (StablePositionComponent)
• ***** flecs Frameworks, iterate components via queries

Contributing

I try to implement the ECS-examples as good as possible for each framework, if you have any improvements, feel free to make a PR or open an issue.

You can find the frameworks example(s) in src/ and benchmark benchmarks/ for more details.
Also you can write tests for the framework example :) and add some metadata in info.json.

TODO: make more detailed "how to add framework"

Read CONTRIBUTING.md for more details.

Run Benchmarks

1. Configure and build benchmarks, see Building Details:
   1. git submodule update --init --recursive
   2. cmake -S . -B ./build
   3. cmake --build ./build
2. Run benchmark(s), with run-benchmarks.sh or each:
   • ./build/benchmark/benchmarks/entt/ecs-benchmark-entt (console output) (optional)
   • ./build/benchmark/benchmarks/entt/ecs-benchmark-entt --benchmark_format=json > ./reports/entt.json (write json report)
3. Plot Reports, after generating json reports, see plot-results.sh:
   1. python3 ./scripts/gen-benchmark-report -i ./info.json gen-plot ./reports/entityx.json ./reports/entt.json ./reports/ginseng.json ./reports/mustache.json ./reports/openecs.json ./reports/flecs.json (generate graphs)
   2. python3 ./scripts/gen-benchmark-report -i ./info.json gen-results-md ./reports/entityx.json ./reports/entt.json ./reports/ginseng.json ./reports/mustache.json ./reports/openecs.json ./reports/flecs.json (generate full report)

You need python and some dependencies to run gen-benchmark-report

Links and More

• Dependency Setup
• Building Details
• Project Template, mix of: starter_template and ModernCppStarter
• Google benchmark
• https://github.com/SanderMertens/ecs-faq
• https://github.com/jslee02/awesome-entity-component-system

Candidates

EntityX by @alecthomas

Entity Component Systems (ECS) are a form of decomposition that completely decouples entity logic and data from the entity "objects" themselves. The Evolve your Hierarchy article provides a solid overview of EC systems and why you should use them.

Version: 1.1.2 (Dec 2021)

EnTT by @skypjack

EnTT is a header-only, tiny and easy to use library for game programming and much more written in modern C++.

Version: 3.10.1

Ginseng by @apples

Ginseng is an entity-component-system (ECS) library designed for use in games.
The main advantage over similar libraries is that the component types do not need to be listed or registered. Component types are detected dynamically.
Any function-like object can be used as a system. The function's parameters are used to determine the required components.

Version: 1.1 (Dec 2021)

mustache by @kirillochnev

A fast, modern C++ Entity Component System

Version: 0.2 (Feb 2022)

OpenEcs by @Gronis

Open Ecs is an Entity Component System that uses metaprogramming, cache coherency, and other useful tricks to maximize performance and configurability. It is written in c++11 without further dependencies.

Version: Beta (Apr 2017)

Flecs by @SanderMertens

Flecs is a fast and lightweight Entity Component System that lets you build games and simulations with millions of entities.

Version: v2.4.8 (Mai 2022)

Deprecated

I removed anax and Artemis-Cpp, they are out-of-date and didn't receive any updates in the last time.
You can still checkout the old versions and branches.