Unity Mono vs Il2cpp vs NET 6 vs NativeAOT (CoreRT)

GC Benchmark

using System;
using System.Diagnostics;

namespace ConsoleApp1
{
	class Program
	{
		static void Main(string[] args)
		{
			//			stopwatch.Restart();
			//benchmark.Run();

			//			time = stopwatch.ElapsedTicks;
			//Benchmarks.MainFake();
			//var watch = Stopwatch.StartNew();
			//BenchGC.RunClasses();
			//watch.Stop();
			//Console.WriteLine(watch.ElapsedTicks);
			GC.Collect();
			var watch = Stopwatch.StartNew();
			BenchGC.RunStrings();
			watch.Stop();
			Console.WriteLine(watch.ElapsedTicks);

			GC.Collect();

			watch = Stopwatch.StartNew();
			BenchGC.RunClasses();
			watch.Stop();
			Console.WriteLine(watch.ElapsedTicks);

			GC.Collect();

			watch = Stopwatch.StartNew();
			BenchGC.RunArrays();
			watch.Stop();
			Console.WriteLine(watch.ElapsedTicks);

			Console.ReadLine();
		}
	}
	class BenchGC
	{
		public static int RunStrings()
		{
			string text = "Hello";
			int a = 0;
			for(int i = 0; i < 1_000_000_000; i++)
			{
				text = text.Substring(0, text.Length - 1);
				a += text.Length;
				text += "a";
			}
			return text.Length;
		}

		public static float RunClasses()
		{
			ClassTest test;
			float a= 0;
			for(int j = 0; j < 5; j++)
			{
				for(int i = 0; i < 1_000_000_000; i++)
				{
					test = new ClassTest();
					test.Test1 = i;
					a += test.Test1;
				}
			}
			return a;
		}
		public static float RunStructs()
		{
			StructTest test;
			float a= 0;
			for(int i = 0; i < 1_000_000_000; i++)
			{
				test = new StructTest();
				test.Test1 = i;
				a += test.Test1;
			}
			return a;
		}

		public static int RunArrays()
		{
			int[] test;
			int a = 0;
			for(int i = 0; i < 300_000; i++)
			{
				test = new int[i];
				a += test.Length;
			}
			return a;
		}
	}
	class ClassTest
	{
		public float Test1;
		public float Test2;
		public float Test3;
		public float Test4;
		public float Test5;
		public float Test6;
		public float Test7;
		public float Test8;
		public float Test9;
		public float Test10;
	}
	struct StructTest
	{
		public float Test1;
		public float Test2;
		public float Test3;
		public float Test4;
		public float Test5;
		public float Test6;
		public float Test7;
		public float Test8;
		public float Test9;
		public float Test10;
	}
}

Result: