bench.fs

open BenchmarkDotNet.Attributes
open System.IO
open System.Runtime.CompilerServices

    
[<Interface>]
type ILog =
     abstract Info: string -> unit

module Log =
    
    [<MethodImpl(MethodImplOptions.NoInlining)>]
    let info (env: #ILog) fmt = 
        env.Info fmt
        env.Info fmt
        env.Info fmt
        env.Info fmt
        env.Info fmt
        env.Info fmt
        env.Info fmt
    
[<Struct;NoEquality;NoComparison>]
type AppEnv =
    interface ILog with
        member this.Info msg = TextWriter.Null.WriteLine(msg)

[<MemoryDiagnoser>]
type EnvBenchmark() =
    
    static let message = "hello world"
    
    [<Benchmark(Baseline=true)>]
    member _.ConsoleWriteLine() = 
        TextWriter.Null.WriteLine(message)
        TextWriter.Null.WriteLine(message)
        TextWriter.Null.WriteLine(message)
        TextWriter.Null.WriteLine(message)
        TextWriter.Null.WriteLine(message)
        TextWriter.Null.WriteLine(message)
        TextWriter.Null.WriteLine(message)

    [<Benchmark>]
    member _.LogInfo() = Log.info (AppEnv()) message

results.txt

BenchmarkDotNet=v0.12.0, OS=Windows 10.0.18363
AMD Ryzen 7 2700X, 1 CPU, 16 logical and 8 physical cores
.NET Core SDK=3.1.101
  [Host]     : .NET Core 3.1.1 (CoreCLR 4.700.19.60701, CoreFX 4.700.19.60801), X64 RyuJIT DEBUG
  DefaultJob : .NET Core 3.1.1 (CoreCLR 4.700.19.60701, CoreFX 4.700.19.60801), X64 RyuJIT


|           Method |     Mean |    Error |   StdDev | Ratio | RatioSD | Gen 0 | Gen 1 | Gen 2 | Allocated |
|----------------- |---------:|---------:|---------:|------:|--------:|------:|------:|------:|----------:|
| ConsoleWriteLine | 10.18 ns | 0.279 ns | 0.342 ns |  1.00 |    0.00 |     - |     - |     - |         - |
|          LogInfo | 15.18 ns | 0.377 ns | 0.619 ns |  1.50 |    0.10 |     - |     - |     - |         - |