diff --git a/Rx.NET/Source/benchmarks/Benchmarks.System.Reactive/Benchmarks.System.Reactive.csproj b/Rx.NET/Source/benchmarks/Benchmarks.System.Reactive/Benchmarks.System.Reactive.csproj
index 681394de2e..fffcbad0c8 100644
--- a/Rx.NET/Source/benchmarks/Benchmarks.System.Reactive/Benchmarks.System.Reactive.csproj
+++ b/Rx.NET/Source/benchmarks/Benchmarks.System.Reactive/Benchmarks.System.Reactive.csproj
@@ -21,6 +21,7 @@
 
   <ItemGroup>
     <PackageReference Include="BenchmarkDotNet" Version="0.10.14" />
+    <PackageReference Include="WindowsBase" Version="4.6.1055" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(Configuration)|$(Platform)'=='Rx.net 3.1.1|AnyCPU'">
@@ -35,4 +36,8 @@
     <ProjectReference Include="..\..\tests\Tests.System.Reactive\Tests.System.Reactive.csproj" />
   </ItemGroup>
 
+  <ItemGroup>
+    <Reference Include="System.Windows.Forms" />
+  </ItemGroup>
+
 </Project>
diff --git a/Rx.NET/Source/benchmarks/Benchmarks.System.Reactive/ComparisonAsyncBenchmark.cs b/Rx.NET/Source/benchmarks/Benchmarks.System.Reactive/ComparisonAsyncBenchmark.cs
new file mode 100644
index 0000000000..593c48e9b8
--- /dev/null
+++ b/Rx.NET/Source/benchmarks/Benchmarks.System.Reactive/ComparisonAsyncBenchmark.cs
@@ -0,0 +1,87 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the Apache 2.0 License.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Linq;
+using System.Reactive.Concurrency;
+using System.Reactive.Linq;
+using System.Threading;
+using BenchmarkDotNet.Attributes;
+
+namespace Benchmarks.System.Reactive
+{
+    [MemoryDiagnoser]
+    public class ComparisonAsyncBenchmark
+    {
+        [Params(1, 10, 100, 1000, 10000, 100000, 1000000)]
+        public int N;
+        private int _store;
+
+        IScheduler _scheduler1;
+        IScheduler _scheduler2;
+
+        [GlobalSetup]
+        public void Setup()
+        {
+            _scheduler1 = new EventLoopScheduler();
+            _scheduler2 = new EventLoopScheduler();
+        }
+
+        [Benchmark]
+        public void ObserveOn()
+        {
+            var cde = new CountdownEvent(1);
+
+            Observable.Range(1, N).ObserveOn(_scheduler1)
+                .Subscribe(v => Volatile.Write(ref _store, v), () => cde.Signal());
+
+            if (N <= 1000)
+            {
+                while (cde.CurrentCount != 0) ;
+            }
+            else
+            {
+                cde.Wait();
+            }
+        }
+
+        [Benchmark]
+        public void SubscribeOn()
+        {
+            var cde = new CountdownEvent(1);
+
+            Observable.Range(1, N).SubscribeOn(_scheduler1)
+                .Subscribe(v => Volatile.Write(ref _store, v), () => cde.Signal());
+
+            if (N <= 1000)
+            {
+                while (cde.CurrentCount != 0) ;
+            }
+            else
+            {
+                cde.Wait();
+            }
+        }
+
+        [Benchmark]
+        public void SubscribeOnObserveOn()
+        {
+            var cde = new CountdownEvent(1);
+
+            Observable.Range(1, N)
+                .SubscribeOn(_scheduler1)
+                .ObserveOn(_scheduler2)
+                .Subscribe(v => Volatile.Write(ref _store, v), () => cde.Signal());
+
+            if (N <= 1000)
+            {
+                while (cde.CurrentCount != 0) ;
+            }
+            else
+            {
+                cde.Wait();
+            }
+        }
+    }
+}
diff --git a/Rx.NET/Source/benchmarks/Benchmarks.System.Reactive/ComparisonBenchmark.cs b/Rx.NET/Source/benchmarks/Benchmarks.System.Reactive/ComparisonBenchmark.cs
new file mode 100644
index 0000000000..4d6a92c9a1
--- /dev/null
+++ b/Rx.NET/Source/benchmarks/Benchmarks.System.Reactive/ComparisonBenchmark.cs
@@ -0,0 +1,306 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the Apache 2.0 License.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Reactive.Concurrency;
+using System.Reactive.Disposables;
+using System.Reactive.Linq;
+using System.Reactive.Subjects;
+using System.Threading;
+using BenchmarkDotNet.Attributes;
+
+namespace Benchmarks.System.Reactive
+{
+    [MemoryDiagnoser]
+    public class ComparisonBenchmark
+    {
+        [Params(1, 10, 100, 1000, 10000, 100000, 1000000)]
+        public int N;
+        private int _store;
+
+        [Benchmark]
+        public void ForLoopBaseLine()
+        {
+            var n = N;
+            for (var i = 0; i < N; i++)
+            {
+                Volatile.Write(ref _store, i);
+            }
+        }
+
+        [Benchmark]
+        public void EnumerableBaseLine()
+        {
+            foreach (var v in Enumerable.Range(1, N))
+            {
+                Volatile.Write(ref _store, v);
+            }
+        }
+
+        [Benchmark]
+        public void Return()
+        {
+            Observable.Return(1).Subscribe(v => Volatile.Write(ref _store, v));
+        }
+
+        [Benchmark]
+        public void Range()
+        {
+            Observable.Range(1, N).Subscribe(v => Volatile.Write(ref _store, v));
+        }
+
+        [Benchmark]
+        public void Select()
+        {
+            Observable.Range(1, N)
+                .Select(v => v + 1)
+                .Subscribe(v => Volatile.Write(ref _store, v));
+        }
+
+        [Benchmark]
+        public void SelectSelect()
+        {
+            Observable.Range(1, N)
+                .Select(v => v + 1)
+                .Select(v => v + 1)
+                .Subscribe(v => Volatile.Write(ref _store, v));
+        }
+
+        [Benchmark]
+        public void Where()
+        {
+            Observable.Range(1, 2 * N)
+                .Where(v => (v & 1) != 0)
+                .Subscribe(v => Volatile.Write(ref _store, v));
+        }
+
+        [Benchmark]
+        public void WhereWhere()
+        {
+            Observable.Range(1, 4 * N)
+                .Where(v => (v & 1) != 0)
+                .Where(v => (v & 2) != 0)
+                .Subscribe(v => Volatile.Write(ref _store, v));
+        }
+
+        [Benchmark]
+        public void Take()
+        {
+            Observable.Range(1, 2 * N)
+                .Take(N)
+                .Subscribe(v => Volatile.Write(ref _store, v));
+        }
+
+        [Benchmark]
+        public void Skip()
+        {
+            Observable.Range(1, 2 * N)
+                .Skip(N)
+                .Subscribe(v => Volatile.Write(ref _store, v));
+        }
+
+        [Benchmark]
+        public void TakeUntil()
+        {
+            Observable.Range(1, N)
+                .TakeUntil(Observable.Never<int>())
+                .Subscribe(v => Volatile.Write(ref _store, v));
+        }
+
+        [Benchmark]
+        public void ToObservable()
+        {
+            Enumerable.Range(1, N)
+                .ToObservable()
+                .Subscribe(v => Volatile.Write(ref _store, v));
+        }
+
+        [Benchmark]
+        public void Concat()
+        {
+            var M = N - N / 2;
+
+            Observable.Concat(
+                    Observable.Range(1, N),
+                    Observable.Range(1, M)
+                )
+                .Subscribe(v => Volatile.Write(ref _store, v));
+        }
+
+        [Benchmark]
+        public void ConcatCrossMap()
+        {
+            var M = 1000 * 1000 / N;
+
+            Observable.Concat(Observable.Range(1, N).Select(v => Observable.Range(v, M)))
+                .Subscribe(v => Volatile.Write(ref _store, v));
+        }
+
+        [Benchmark]
+        public void SelectManyCrossMap()
+        {
+            var M = 1000 * 1000 / N;
+
+            Observable.Range(1, N).SelectMany(v => Observable.Range(v, M))
+                .Subscribe(v => Volatile.Write(ref _store, v));
+        }
+
+        [Benchmark]
+        public void MergeCrossMap()
+        {
+            var M = 1000 * 1000 / N;
+
+            Observable.Merge(Observable.Range(1, N)
+                    .Select(v => Observable.Range(v, M))
+                )
+                .Subscribe(v => Volatile.Write(ref _store, v));
+        }
+
+        [Benchmark]
+        public void AsyncSubjectPush()
+        {
+            var subj = new AsyncSubject<int>();
+            subj.Subscribe(v => Volatile.Write(ref _store, v));
+
+            var n = N;
+            for (var i = 0; i < N; i++)
+            {
+                subj.OnNext(i);
+            }
+            subj.OnCompleted();
+        }
+
+        [Benchmark]
+        public void SubjectPush()
+        {
+            var subj = new Subject<int>();
+            subj.Subscribe(v => Volatile.Write(ref _store, v));
+
+            var n = N;
+            for (var i = 0; i < N; i++)
+            {
+                subj.OnNext(i);
+            }
+            subj.OnCompleted();
+        }
+
+        [Benchmark]
+        public void AmbTwo()
+        {
+            Observable.Never<int>().Amb(Observable.Range(1, N))
+                .Subscribe(v => Volatile.Write(ref _store, v));
+        }
+
+        [Benchmark]
+        public void AmbThree()
+        {
+            Observable.Amb(Observable.Never<int>(), Observable.Never<int>(), Observable.Range(1, N))
+                .Subscribe(v => Volatile.Write(ref _store, v));
+        }
+
+        [Benchmark]
+        public void Timeout()
+        {
+            Observable.Range(1, N)
+                .Timeout(TimeSpan.FromHours(1))
+                .Subscribe(v => Volatile.Write(ref _store, v));
+        }
+
+#pragma warning disable CS0618 // Type or member is obsolete
+        [Benchmark]
+        public void First()
+        {
+            Volatile.Write(ref _store, Observable.Range(1, N)
+                .First());
+        }
+
+        [Benchmark]
+        public void Last()
+        {
+            Volatile.Write(ref _store, Observable.Range(1, N)
+                .Last());
+        }
+#pragma warning restore CS0618 // Type or member is obsolete
+
+        private IList<int> _bufferStore;
+
+        [Benchmark]
+        public void Buffer_Exact()
+        {
+            Observable.Range(1, 1000)
+                .Buffer(1)
+                .Subscribe(v => Volatile.Write(ref _bufferStore, v));
+        }
+
+        [Benchmark]
+        public void Buffer_Skip()
+        {
+            Observable.Range(1, 1000)
+                .Buffer(1, 2)
+                .Subscribe(v => Volatile.Write(ref _bufferStore, v));
+        }
+
+        [Benchmark]
+        public void Buffer_Overlap()
+        {
+            Observable.Range(1, 1000)
+                .Buffer(2, 1)
+                .Subscribe(v => Volatile.Write(ref _bufferStore, v));
+        }
+
+        [Benchmark]
+        public void CurrentThreadSchedulerRepeated()
+        {
+            var n = N;
+            var scheduler = CurrentThreadScheduler.Instance;
+            for (var i = 0; i < n; i++)
+            {
+                scheduler.Schedule(i, (_, v) =>
+                {
+                    Volatile.Write(ref _store, v);
+                    return Disposable.Empty;
+                });
+            }
+        }
+
+        [Benchmark]
+        public void TakeLast()
+        {
+            Observable.Range(1, 2 * N).TakeLast(N)
+                .Subscribe(v => Volatile.Write(ref _store, v));
+        }
+
+        [Benchmark]
+        public void Repeat()
+        {
+            Observable.Repeat(1, N)
+                .Subscribe(v => Volatile.Write(ref _store, v));
+        }
+
+        [Benchmark]
+        public void ToList()
+        {
+            Observable.Repeat(1, N).ToList()
+                .Subscribe(v => Volatile.Write(ref _bufferStore, v));
+        }
+
+        [Benchmark]
+        public void Generate()
+        {
+            Observable.Generate(0, s => s < N, s => s + 1, s => s)
+                .Subscribe(v => Volatile.Write(ref _store, v));
+        }
+
+        [Benchmark]
+        public void Collect()
+        {
+            foreach (var v in Observable.Range(1, N).Collect(() => new List<int>(), (a, b) => { a.Add(b); return a; }))
+            {
+                Volatile.Write(ref _bufferStore, v);
+            }
+        }
+    }
+}
diff --git a/Rx.NET/Source/benchmarks/Benchmarks.System.Reactive/Program.cs b/Rx.NET/Source/benchmarks/Benchmarks.System.Reactive/Program.cs
index d0b5ce171d..805f0a9d8e 100644
--- a/Rx.NET/Source/benchmarks/Benchmarks.System.Reactive/Program.cs
+++ b/Rx.NET/Source/benchmarks/Benchmarks.System.Reactive/Program.cs
@@ -21,8 +21,9 @@ private static void Main()
                 typeof(BufferCountBenchmark),
                 typeof(RangeBenchmark),
                 typeof(ToObservableBenchmark),
-                typeof(RepeatBenchmark)
-
+                typeof(RepeatBenchmark),
+                typeof(ComparisonBenchmark),
+                typeof(ComparisonAsyncBenchmark)
 #if (CURRENT)
                 ,typeof(AppendPrependBenchmark)
 #endif