Comparing read-write speed of Unity's ECS native container against regular arrays. Read-write linearly.

ECSContainerSpeedTest.cs

using UnityEngine;
using Unity.Entities;
using Unity.Mathematics;
using Unity.Collections;
using Unity.Jobs;

using UnityEngine.Experimental.PlayerLoop;

using System.Collections.Generic;
using System.Diagnostics;

public class Sandbox : JobComponentSystem
{
    NativeArray<int> nativeArray;
    int[] array;
    private const int amount = 100000;
    Stopwatch sw;
    protected override void OnCreateManager(int capacity)
    {
        nativeArray = new NativeArray<int>(amount, Allocator.Persistent);
        array = new int[amount];
        // for (int i = 0; i < amount; i++)
        // {
        //     int random = UnityEngine.Random.Range(0,100);
        //     nativeArray[i] = random;
        //     array[i] = random;
        // }
        sw = new Stopwatch();
    }
    
    protected override void OnDestroyManager()
    {
        nativeArray.Dispose();
    }

    protected override JobHandle OnUpdate(JobHandle inputDeps)
    {
        int random = UnityEngine.Random.Range(0,100);
        int read = 0;

        WarmUp(array);
        sw.Start();
        for (int i = 0; i < amount; i++)
        {
            read = array[i];
        }
        sw.Stop();
        UnityEngine.Debug.Log($"{nameof(array)} R {sw.ElapsedTicks}");
        sw.Reset();

        WarmUp(nativeArray);
        sw.Start();
        for (int i = 0; i < amount; i++)
        {
            read = nativeArray[i];
        }
        sw.Stop();
        UnityEngine.Debug.Log($"{nameof(nativeArray)} R {sw.ElapsedTicks}");
        sw.Reset();

        WarmUp(array);
        sw.Start();
        for (int i = 0; i < amount; i++)
        {
            array[i] = random;
        }
        sw.Stop();
        UnityEngine.Debug.Log($"{nameof(array)} W {sw.ElapsedTicks}");
        sw.Reset();

        WarmUp(nativeArray);
        sw.Start();
        for (int i = 0; i < amount; i++)
        {
            nativeArray[i] = random;
        }
        sw.Stop();
        UnityEngine.Debug.Log($"{nameof(nativeArray)} W {sw.ElapsedTicks}");
        sw.Reset();

        WarmUp(array);
        sw.Start();
        for (int i = 0; i < amount; i++)
        {
            array[i]++;
        }
        sw.Stop();
        UnityEngine.Debug.Log($"{nameof(array)} RW {sw.ElapsedTicks}");
        sw.Reset();

        WarmUp(nativeArray);
        sw.Start();
        for (int i = 0; i < amount; i++)
        {
            nativeArray[i]++;
        }
        sw.Stop();
        UnityEngine.Debug.Log($"{nameof(nativeArray)} RW {sw.ElapsedTicks}");
        sw.Reset();

        var rwJob = new RWJob() { nativeArray = nativeArray };
        rwJob.Schedule().Complete(); //Warm up
        sw.Start();
        rwJob.Schedule().Complete();
        sw.Stop();
        UnityEngine.Debug.Log($"{nameof(nativeArray)} RW (Job) {sw.ElapsedTicks}");
        sw.Reset();

        int[] sizes = new int[] { 1, 2, 4, 8, 16, 32, 64, 128, 256 };
        foreach (int size in sizes)
        {
            var rwJobParallel = new RWJobParallel() { nativeArray = nativeArray };
            rwJobParallel.Schedule(amount, size).Complete(); //Warm up
            sw.Start();
            rwJobParallel.Schedule(amount, size).Complete();
            sw.Stop();
            UnityEngine.Debug.Log($"{nameof(nativeArray)} RW (Job Parallel {size}) {sw.ElapsedTicks}");
            sw.Reset();
        }

        this.Enabled = false;
        return inputDeps;
    }

    struct RWJob : IJob
    {
        public NativeArray<int> nativeArray;
        public void Execute()
        {
            for (int i = 0; i < amount; i++)
            {
                nativeArray[i]++;
            }
        }
    }

    struct RWJobParallel : IJobParallelFor
    {
        public NativeArray<int> nativeArray;
        public void Execute(int index)
        {
            nativeArray[index]++;
        }
    }


    private static void WarmUp(int[] a)
    {
        int random = UnityEngine.Random.Range(0, 100);
        for (int i = 0; i < a.Length; i++)
        {
            a[i] = random;
        }
    }

    private static void WarmUp(NativeArray<int> a)
    {
        int random = UnityEngine.Random.Range(0, 100);
        for (int i = 0; i < a.Length; i++)
        {
            a[i] = random;
        }
    }

}