How to benchmark different .NET versions

With the famous BenchmarkDotNet library you can benchmark a lot - but it doesn't stop with a single .NET version. You can benchmark multiple versions of the same code that targets different runtimes!

The setup

To run multiple versions of your code, you have to select multiple target frameworks in your csproj file:

<Project Sdk="Microsoft.NET.Sdk">

    <PropertyGroup>
        <OutputType>Exe</OutputType>
        <ImplicitUsings>enable</ImplicitUsings>
        <Nullable>enable</Nullable>
        <LangVersion>preview</LangVersion>
        <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
        <TargetFrameworks>net7.0;net8.0</TargetFrameworks>
    </PropertyGroup>

    <ItemGroup>
      <PackageReference Include="BenchmarkDotNet" Version="0.13.6" />
    </ItemGroup>

</Project>

Then inside your BenchmarkDotNet test you can define via the SimpleJobAttribute the target runtime.

[SimpleJob(RuntimeMoniker.Net70, baseline: true)]
[SimpleJob(RuntimeMoniker.Net80)]
[MemoryDiagnoser]
public class InterpolatedEnumBenchmark
{
    [Benchmark]
    public string Interpolated()
        => $"{Weekdays.Monday} {Weekdays.Tuesday} {Weekdays.Wednesday} {Weekdays.Thursday} {Weekdays.Friday} {Weekdays.Saturday} {Weekdays.Sunday}";
}

public enum Weekdays
{
    Monday,
    Tuesday,
    Wednesday,
    Thursday,
    Friday,
    Saturday,
    Sunday
}

The result will look like this:

BenchmarkDotNet v0.13.6, macOS Ventura 13.4.1 (22F82) [Darwin 22.5.0]
Apple M1 Pro, 1 CPU, 10 logical and 10 physical cores
.NET SDK 8.0.100-preview.6.23330.14
  [Host]   : .NET 7.0.5 (7.0.523.17405), Arm64 RyuJIT AdvSIMD
  .NET 7.0 : .NET 7.0.5 (7.0.523.17405), Arm64 RyuJIT AdvSIMD
  .NET 8.0 : .NET 8.0.0 (8.0.23.32907), Arm64 RyuJIT AdvSIMD


|       Method |      Job |  Runtime |      Mean |    Error |   StdDev | Ratio |   Gen0 | Allocated | Alloc Ratio |
|------------- |--------- |--------- |----------:|---------:|---------:|------:|-------:|----------:|------------:|
| Interpolated | .NET 7.0 | .NET 7.0 | 148.66 ns | 2.008 ns | 1.780 ns |  1.00 | 0.0484 |     304 B |        1.00 |
| Interpolated | .NET 8.0 | .NET 8.0 |  61.37 ns | 0.888 ns | 0.831 ns |  0.41 | 0.0216 |     136 B |        0.45 |