Hi, I made a benchmark of the ecs systems of unity to compare its performance to the one found in the amethyst game engine (uses "specs" ecs). I would like someone that knows the ecs in depth to look at my code and make sure my benchmark is valid and I didn't accidentally make an error that would lower the performance of unity. The code is available here: https://github.com/jojolepro/unityecsbench/tree/master/Assets/Scenes How it works: I have 3 components: Comp1, Comp2, Comp3 I create 3 millions entities according to the following distribution: 1 million: Comp1 1 million: (Comp1 & Comp2) 1 million: (Comp1 & Comp2 & Comp3) Then I iterate over all the entities using 3 different systems in readonly, making sure to access the data of each. Sys1: Comp1 -> 3 million iter Sys2: (Comp1 & Comp2) -> 2 million iter Sys3: (Comp2 & Comp3) -> 1million iter Each update frame takes a total of 45 seconds to complete (which is REALLY slow for the amount of entities, considering specs can do the same in 8 ms). Testing was made by exporting the game, and running it from the command line using -nographics -batchmode Logs are in the default log location of your system with the benchmark results. Compiling on linux was impossible, so I could only test on windows. A built exe of the game is available in the repo under the Build/ directory. Let me know your results and thanks for your time!