Benchmarking downloading a file with HttpClient

Program.cs

// Run with:
//  export DOTNET_TieredCompilation=0
//  dotnet run -c Release

using System.Buffers;
using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Running;

BenchmarkRunner.Run<Benchmarks>(args: args);

[MediumRunJob]
public class Benchmarks
{
    // From https://github.com/dotnet/runtime/blob/main/src/libraries/System.Private.CoreLib/src/System/IO/Stream.cs#L126
    const int DefaultCopyBufferSize = 81920;

    // 478MB file
    const string URL = "http://10.5.2.105/videos/Shows/Channel%209/RB_XNA_Launch.wmv";
    const string DEST = "/tmp/RB_XNA_Launch.wmv";

    static HttpClient client = new HttpClient();

    [Benchmark(Baseline = true)]
    public async Task CopyToAsync()
    {
        using var httpStream = await client.GetStreamAsync(URL);
        using var fileStream = File.Create(DEST);
        await httpStream.CopyToAsync(fileStream, DefaultCopyBufferSize);
    }

    [Benchmark]
    [Arguments(0, 0)]
    [Arguments(2, 1)]
    [Arguments(5, 1)]
    [Arguments(10, 1)]
    public async Task CopyWithDelay(int delayEvery, int delay)
    {
        using var httpStream = await client.GetStreamAsync(URL);
        using var fileStream = File.Create(DEST);

        byte[] buffer = ArrayPool<byte>.Shared.Rent(DefaultCopyBufferSize);
        try
        {
            long iterations = 0;
            int bytesRead;
            while ((bytesRead = await httpStream.ReadAsync(new Memory<byte>(buffer))) != 0)
            {
                await fileStream.WriteAsync(new ReadOnlyMemory<byte>(buffer, 0, bytesRead));
                if (++iterations == delayEvery)
                {
                    Thread.Sleep(delay);
                    iterations = 0;
                }
            }
        }
        finally
        {
            ArrayPool<byte>.Shared.Return(buffer);
        }
    }
}

results.md

BenchmarkDotNet v0.14.0, Ubuntu 22.04.4 LTS (Jammy Jellyfish)
AMD Ryzen Threadripper PRO 3955WX 16-Cores, 1 CPU, 32 logical and 16 physical cores
1Gbps network connection to remote server

.NET SDK 8.0.401
  [Host]    : .NET 8.0.8 (8.0.824.36612), X64 RyuJIT AVX2
  MediumRun : .NET 8.0.8 (8.0.824.36612), X64 RyuJIT AVX2

Job=MediumRun  IterationCount=15  LaunchCount=2  
WarmupCount=10  
DOTNET_TieredCompilation=0

Method	delayEvery	delay	Mean	Error	StdDev
CopyToAsync	?	?	5.322 s	0.2452 s	0.3437 s
CopyWithDelay	0	0	5.369 s	0.1769 s	0.2593 s
CopyWithDelay	2	1	5.374 s	0.1189 s	0.1780 s
CopyWithDelay	5	1	5.364 s	0.1672 s	0.2451 s
CopyWithDelay	10	1	5.368 s	0.1187 s	0.1740 s
CopyWithDelay	10	10	10.735 s	3.1946 s	4.6826 s