Unity ECS filter speed SetFilter vs. ForEachFilter printed on the console as CSV (Result : https://gist.github.com/5argon/1bb412d218eb6872418fe2f867a20435)

FilteringSpeed.cs

using System.Collections.Generic;
using NUnit.Framework;
using System.Linq;

using Unity.Entities;
using Unity.Collections;

using System.Diagnostics;
public struct IntData : IComponentData { public int data; public override string ToString() => data.ToString(); }
public struct Category : ISharedComponentData { public int category; }

public class FilteringSpeed : TestBase
{
    private class CS : ComponentSystem
    {
        struct InjectedGroup
        {
            public ComponentDataArray<IntData> datas;
            [ReadOnly] public SharedComponentDataArray<Category> category;
            public readonly int GroupIndex;
        }
        [Inject] InjectedGroup injectedGroup;

        protected override void OnUpdate() { }

        public void SetFilterTest(Stopwatch sw, int category)
        {
            UpdateInjectedComponentGroups();
            var cg = ComponentGroups[injectedGroup.GroupIndex];
            sw.Start();
            for (int i = 0; i < category; i++)
            {
                cg.SetFilter(new Category { category = i });
                var cda = cg.GetComponentDataArray<IntData>();
                for (int ij = 0; ij < cda.Length; ij++)
                {
                    var d = cda[ij];
                    d.data++;
                    cda[ij] = d;
                }
            }
            sw.Stop();
        }

        public void ForEachFilterTest(Stopwatch sw, int category)
        {
            UpdateInjectedComponentGroups();
            var cg = ComponentGroups[injectedGroup.GroupIndex];
            sw.Start();
            var l = new List<Category>();
            for (int i = 0; i < category; i++)
            {
                l.Add(new Category { category = i });
            }
            using (var filter = cg.CreateForEachFilter(l))
            {
                for (int i = 0; i < category; i++)
                {
                    var cda = cg.GetComponentDataArray<IntData>(filter,i);
                    for (int ij = 0; ij < cda.Length; ij++)
                    {
                        var d = cda[ij];
                        d.data++;
                        cda[ij] = d;
                    }
                }
            }
            sw.Stop();
        }
    }

    [Test]
    public void RunTest([Values(10,100,1000)]  int entitiesPerCategory, [Values(5,10,25,50,100,1000)] int kindsOfCategory, [Values(1,3,5,10,50,100)] int categoryToFilter)
    {
        if(categoryToFilter > kindsOfCategory)
        {
            UnityEngine.Debug.Log($"0,0,0,0,0");
            Assert.Fail();
        }

        var w = new World("TestWorld");
        var em = w.GetOrCreateManager<EntityManager>();
        var cs = w.CreateManager<CS>();

        var eet = em.BeginExclusiveEntityTransaction();
        for (int j = 0; j < kindsOfCategory; j++)
        {
            for (int i = 0; i < entitiesPerCategory; i++)
            {
                var e = eet.CreateEntity(typeof(IntData), typeof(Category));
                eet.SetComponentData(e, new IntData { data = i });
                eet.SetSharedComponentData(e, new Category { category = j });
            }
        }
        em.EndExclusiveEntityTransaction();

        Stopwatch swSetFilter = new Stopwatch();
        Stopwatch swForEachFilter = new Stopwatch();

        List<long> setFilterResults = new List<long>();
        List<long> forEachFilterResults = new List<long>();

        for (int i = 0; i < 10; i++)
        {
            swSetFilter.Reset();
            swForEachFilter.Reset();
            cs.SetFilterTest(swSetFilter, categoryToFilter);
            cs.ForEachFilterTest(swForEachFilter, categoryToFilter);
            if(i != 0)
            {
                setFilterResults.Add(swSetFilter.ElapsedTicks);
                forEachFilterResults.Add(swForEachFilter.ElapsedTicks);
            }
        }
        UnityEngine.Debug.Log($"{entitiesPerCategory},{kindsOfCategory},{categoryToFilter},{setFilterResults.Average()},{forEachFilterResults.Average()}");
    }
}