InterfaceCastBenchmark.cs

using System.Collections.Generic;
using BenchmarkDotNet.Attributes;

public class P
{
    static void Main(string[] args)
    {
        BenchmarkDotNet.Running.BenchmarkSwitcher.FromAssembly(typeof(P).Assembly).Run(args);
    }

    public static IEnumerable<object> TestData()
    {
        yield return new Interfaces1();
        yield return new Interfaces6();
        yield return new Interfaces16();
    }

    [Benchmark(Baseline = true)]
    [ArgumentsSource(nameof(TestData))]
    public bool IsInterface1(object o) => o is Interface1;

    [Benchmark()]
    [ArgumentsSource(nameof(TestData))]
    public bool IsInterface2(object o) => o is Interface2;

    [Benchmark()]
    [ArgumentsSource(nameof(TestData))]
    public bool IsInterface3(object o) => o is Interface3;

    [Benchmark()]
    [ArgumentsSource(nameof(TestData))]
    public bool IsInterface4(object o) => o is Interface4;

    [Benchmark()]
    [ArgumentsSource(nameof(TestData))]
    public bool IsInterface5(object o) => o is Interface5;

    [Benchmark()]
    [ArgumentsSource(nameof(TestData))]
    public bool IsInterface6(object o) => o is Interface6;

    [Benchmark()]
    [ArgumentsSource(nameof(TestData))]
    public bool IsInterface7(object o) => o is Interface7;

    [Benchmark()]
    [ArgumentsSource(nameof(TestData))]
    public bool IsInterface8(object o) => o is Interface8;

    [Benchmark()]
    [ArgumentsSource(nameof(TestData))]
    public bool IsInterface9(object o) => o is Interface9;

    [Benchmark()]
    [ArgumentsSource(nameof(TestData))]
    public bool IsInterface10(object o) => o is Interface10;

    [Benchmark()]
    [ArgumentsSource(nameof(TestData))]
    public bool IsInterface11(object o) => o is Interface11;

    [Benchmark()]
    [ArgumentsSource(nameof(TestData))]
    public bool IsInterface12(object o) => o is Interface12;

    [Benchmark()]
    [ArgumentsSource(nameof(TestData))]
    public bool IsInterface13(object o) => o is Interface13;

    [Benchmark()]
    [ArgumentsSource(nameof(TestData))]
    public bool IsInterface14(object o) => o is Interface14;

    [Benchmark()]
    [ArgumentsSource(nameof(TestData))]
    public bool IsInterface15(object o) => o is Interface15;

    [Benchmark()]
    [ArgumentsSource(nameof(TestData))]
    public bool IsInterface16(object o) => o is Interface16;

    [Benchmark()]
    [ArgumentsSource(nameof(TestData))]
    public bool IsNotImplemented(object o) => o is UnimplmentedInterface;
}

public class NoInterfaces { }
public class Interfaces1 : Interface1 { }
public class Interfaces2 : Interface1, Interface2 { }
public class Interfaces3 : Interface1, Interface2, Interface3 { }
public class Interfaces4 : Interface1, Interface2, Interface3, Interface4 { }
public class Interfaces5 : Interface1, Interface2, Interface3, Interface4, Interface5 { }
public class Interfaces6 : Interface1, Interface2, Interface3, Interface4, Interface5, Interface6 { }
public class Interfaces7 : Interface1, Interface2, Interface3, Interface4, Interface5, Interface6, Interface7 { }
public class Interfaces8 : Interface1, Interface2, Interface3, Interface4, Interface5, Interface6, Interface7, Interface8 { }
public class Interfaces9 : Interface1, Interface2, Interface3, Interface4, Interface5, Interface6, Interface7, Interface8, Interface9 { }
public class Interfaces10 : Interface1, Interface2, Interface3, Interface4, Interface5, Interface6, Interface7, Interface8, Interface9, Interface10 { }
public class Interfaces11 : Interface1, Interface2, Interface3, Interface4, Interface5, Interface6, Interface7, Interface8, Interface9, Interface10, Interface11 { }
public class Interfaces12 : Interface1, Interface2, Interface3, Interface4, Interface5, Interface6, Interface7, Interface8, Interface9, Interface10, Interface11, Interface12 { }
public class Interfaces13 : Interface1, Interface2, Interface3, Interface4, Interface5, Interface6, Interface7, Interface8, Interface9, Interface10, Interface11, Interface12, Interface13 { }
public class Interfaces14 : Interface1, Interface2, Interface3, Interface4, Interface5, Interface6, Interface7, Interface8, Interface9, Interface10, Interface11, Interface12, Interface13, Interface14 { }
public class Interfaces15 : Interface1, Interface2, Interface3, Interface4, Interface5, Interface6, Interface7, Interface8, Interface9, Interface10, Interface11, Interface12, Interface13, Interface14, Interface15 { }
public class Interfaces16 : Interface1, Interface2, Interface3, Interface4, Interface5, Interface6, Interface7, Interface8, Interface9, Interface10, Interface11, Interface12, Interface13, Interface14, Interface15, Interface16 { }

public interface Interface1 { }
public interface Interface2 { }
public interface Interface3 { }
public interface Interface4 { }
public interface Interface5 { }
public interface Interface6 { }
public interface Interface7 { }
public interface Interface8 { }
public interface Interface9 { }
public interface Interface10 { }
public interface Interface11 { }
public interface Interface12 { }
public interface Interface13 { }
public interface Interface14 { }
public interface Interface15 { }
public interface Interface16 { }
public interface UnimplmentedInterface { }