diff --git a/src/Aardvark.Base.IO/Aardvark.Base.IO.csproj b/src/Aardvark.Base.IO/Aardvark.Base.IO.csproj
index 79bddd65..6f10d564 100644
--- a/src/Aardvark.Base.IO/Aardvark.Base.IO.csproj
+++ b/src/Aardvark.Base.IO/Aardvark.Base.IO.csproj
@@ -5,7 +5,7 @@
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <NoWarn>612;1591</NoWarn>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <LangVersion>8.0</LangVersion>
+    <LangVersion>9.0</LangVersion>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">
     <OutputPath>..\..\bin\Debug</OutputPath>
diff --git a/src/Aardvark.Base.Tensors.CSharp/Aardvark.Base.Tensors.CSharp.csproj b/src/Aardvark.Base.Tensors.CSharp/Aardvark.Base.Tensors.CSharp.csproj
index 2478e6e9..652d3f6b 100644
--- a/src/Aardvark.Base.Tensors.CSharp/Aardvark.Base.Tensors.CSharp.csproj
+++ b/src/Aardvark.Base.Tensors.CSharp/Aardvark.Base.Tensors.CSharp.csproj
@@ -3,7 +3,7 @@
   <PropertyGroup>
     <OutputType>Library</OutputType>
     <TargetFramework>netstandard2.0</TargetFramework>
-    <LangVersion>8.0</LangVersion>
+    <LangVersion>9.0</LangVersion>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <NoWarn>1591</NoWarn>
   </PropertyGroup>
diff --git a/src/Aardvark.Base/Aardvark.Base.csproj b/src/Aardvark.Base/Aardvark.Base.csproj
index fa6eaba3..af6d61c0 100644
--- a/src/Aardvark.Base/Aardvark.Base.csproj
+++ b/src/Aardvark.Base/Aardvark.Base.csproj
@@ -2,7 +2,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <TargetFrameworks>net8.0;netstandard2.0</TargetFrameworks>
-    <LangVersion>8.0</LangVersion>
+    <LangVersion>9.0</LangVersion>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">
diff --git a/src/Aardvark.Base/Extensions/ArrayExtensions.cs b/src/Aardvark.Base/Extensions/ArrayExtensions.cs
index 3b45a251..a27064b5 100644
--- a/src/Aardvark.Base/Extensions/ArrayExtensions.cs
+++ b/src/Aardvark.Base/Extensions/ArrayExtensions.cs
@@ -2265,7 +2265,7 @@ public static void CopyTo(this Array input, int offset, int length, IntPtr targe
             try
             {
                 var typeSize = input.GetType().GetElementType().GetCLRSize();
-                var dataSize = input.Length * typeSize;
+                var dataSize = length * typeSize;
 
                 unsafe
                 {
@@ -2281,14 +2281,10 @@ public static void CopyTo(this Array input, int offset, int length, IntPtr targe
         }
 
         public static void CopyTo(this Array input, int length, IntPtr target)
-        {
-            CopyTo(input, 0, length, target);
-        }
+            => CopyTo(input, 0, length, target);
 
         public static void CopyTo(this Array input, IntPtr target)
-        {
-            CopyTo(input, 0, input.Length, target);
-        }
+            => CopyTo(input, 0, input.Length, target);
 
         public static void CopyTo(this IntPtr input, Array target, int offset, int length)
         {
@@ -2297,7 +2293,7 @@ public static void CopyTo(this IntPtr input, Array target, int offset, int lengt
             try
             {
                 var typeSize = target.GetType().GetElementType().GetCLRSize();
-                var dataSize = target.Length * typeSize;
+                var dataSize = length * typeSize;
 
                 unsafe
                 {
@@ -2312,15 +2308,10 @@ public static void CopyTo(this IntPtr input, Array target, int offset, int lengt
         }
 
         public static void CopyTo(this IntPtr input, Array target, int length)
-        {
-            CopyTo(input, target, 0, length);
-        }
+            => CopyTo(input, target, 0, length);
 
         public static void CopyTo(this IntPtr input, Array target)
-        {
-            CopyTo(input, target, target.Length);
-        }
-
+            => CopyTo(input, target, target.Length);
 
         public static void CopyTo(this IntPtr input, IntPtr target, int size)
         {
diff --git a/src/Aardvark.Base/Extensions/UnsafeCoerce.cs b/src/Aardvark.Base/Extensions/UnsafeCoerce.cs
index b592a006..fc207aca 100644
--- a/src/Aardvark.Base/Extensions/UnsafeCoerce.cs
+++ b/src/Aardvark.Base/Extensions/UnsafeCoerce.cs
@@ -1,12 +1,31 @@
 using System;
+using System.Collections.Concurrent;
+using System.Reflection;
+using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 
 namespace Aardvark.Base
 {
     public static class ArrayUnsafeCoerceExtensions
     {
+        private static readonly MethodInfo unsafeSizeOfMeth = typeof(Unsafe).GetMethod(nameof(Unsafe.SizeOf), BindingFlags.Public | BindingFlags.Static);
+
+        private static readonly ConcurrentDictionary<Type, int> unsafeTypeSizes = new();
+
+        /// <summary>
+        /// Returns the managed size of the given type.
+        /// </summary>
+        public static int GetCLRSize(this Type t)
+        {
+            return unsafeTypeSizes.GetOrAdd(t, t =>
+            {
+                var mi = unsafeSizeOfMeth.MakeGenericMethod(t);
+                return (int)mi.Invoke(null, null);
+            });
+        }
+
         #region UnsafeCoerce
-        
+
         [Obsolete("breaks net8.0+")]
         public static IntPtr GetTypeIdUncached<T>()
             where T : struct
@@ -32,14 +51,6 @@ private static IntPtr GetTypeId<T>()
             return typeId;
         }
 
-        public static int GetCLRSize(this Type t)
-        {
-            // TODO: somehow make use of sizeof operator -> requires compile time type -> cannot use ILGenerator in .net standard
-            if (t == typeof(char)) return 2; // Marshal.SizeOf = 1
-            if (t == typeof(bool)) return 1; // Marshal.SizeOf = 4
-            return Marshal.SizeOf(t);
-        }
-
         [Obsolete("breaks net8.0+")]
         internal static TR[] UnsafeCoerce<TR>(this Array input, IntPtr targetId)
             where TR : struct
diff --git a/src/Tests/Aardvark.Base.FSharp.Tests/Aardvark.Base.FSharp.Tests.fsproj b/src/Tests/Aardvark.Base.FSharp.Tests/Aardvark.Base.FSharp.Tests.fsproj
index 348ec2d9..92ab4f93 100644
--- a/src/Tests/Aardvark.Base.FSharp.Tests/Aardvark.Base.FSharp.Tests.fsproj
+++ b/src/Tests/Aardvark.Base.FSharp.Tests/Aardvark.Base.FSharp.Tests.fsproj
@@ -34,6 +34,7 @@
     <Compile Include="SortedSetExt.fs" />
     <Compile Include="MapExt.fs" />
     <Compile Include="OrderMaintenanceTrie.fs" />
+    <Compile Include="SizeOfTests.fs" />
     <Compile Include="Program.fs" />
   </ItemGroup>
   <ItemGroup>
diff --git a/src/Tests/Aardvark.Base.FSharp.Tests/SizeOfTests.fs b/src/Tests/Aardvark.Base.FSharp.Tests/SizeOfTests.fs
new file mode 100644
index 00000000..88b7c633
--- /dev/null
+++ b/src/Tests/Aardvark.Base.FSharp.Tests/SizeOfTests.fs
@@ -0,0 +1,25 @@
+namespace Aardvark.Base.FSharp.Tests
+
+open Aardvark.Base
+open System.Runtime.InteropServices
+
+open FsUnit
+open NUnit.Framework
+
+module SizeOfTests =
+
+    [<Struct; StructLayout(LayoutKind.Sequential)>]
+    type MyStruct =
+        val A : bool
+        val B : bool
+        val C : char
+
+    [<Test>]
+    let ``[GetCLRSize] Primitive types``() =
+        typeof<int64>.GetCLRSize() |> should equal 8
+        typeof<bool>.GetCLRSize() |> should equal 1
+        typeof<char>.GetCLRSize() |> should equal 2
+
+    [<Test>]
+    let ``[GetCLRSize] Struct``() =
+        typeof<MyStruct>.GetCLRSize() |> should equal 4