benchmark.cs

using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Running;
using System;
using System.Linq;

[MemoryDiagnoser]
public class ByteArrayChunker
{
    private readonly byte[] data;

    public ByteArrayChunker()
    {
        data = new byte[(16 * 1024) + 23];
        new Random(42).NextBytes(data);
    }

    [Params(-1, 0, 1, 1024, 16 * 1024)]
    public int Offset { get; set; }

    [Benchmark(Baseline = true)]
    public byte[] Skip() => data.Skip(Offset).ToArray();

    [Benchmark]
    public byte[] BlockCopy()
    {
        if (Offset <= 0) return data;
        var chunk = new byte[data.Length - Offset];
        Buffer.BlockCopy(data, Offset, chunk, 0, chunk.Length);
        return chunk;
    }

    [Benchmark]
    public ArraySegment<byte> Segment()
    {
        if (Offset <= 0) return new ArraySegment<byte>(data);
        return new ArraySegment<byte>(data, Offset, data.Length - Offset);
    }
}

public static class Program
{
    public static void Main() => BenchmarkRunner.Run<ByteArrayChunker>();
}

results.md

BenchmarkDotNet=v0.13.2, OS=Windows 11 (10.0.22621.674)
11th Gen Intel Core i7-1185G7 3.00GHz, 1 CPU, 8 logical and 4 physical cores
  [Host]     : .NET Framework 4.8.1 (4.8.9032.0), X64 RyuJIT VectorSize=256
  DefaultJob : .NET Framework 4.8.1 (4.8.9032.0), X64 RyuJIT VectorSize=256


|    Method | Offset |            Mean |         Error |         StdDev |          Median | Ratio |    Gen0 |   Gen1 | Allocated | Alloc Ratio |
|---------- |------- |----------------:|--------------:|---------------:|----------------:|------:|--------:|-------:|----------:|------------:|
|      Skip |     -1 | 151,726.6506 ns | 3,007.3543 ns |  6,664.0894 ns | 150,450.1953 ns | 1.000 | 12.9395 | 0.9766 |   82566 B |        1.00 |
| BlockCopy |     -1 |       0.1605 ns |     0.0581 ns |      0.1252 ns |       0.1152 ns | 0.000 |       - |      - |         - |        0.00 |
|   Segment |     -1 |      10.6340 ns |     0.2361 ns |      0.4196 ns |      10.5082 ns | 0.000 |       - |      - |         - |        0.00 |
|           |        |                 |               |                |                 |       |         |        |           |             |
|      Skip |      0 | 153,767.2458 ns | 3,049.1016 ns |  8,499.6765 ns | 152,686.4502 ns | 1.000 | 12.9395 | 0.9766 |   82566 B |        1.00 |
| BlockCopy |      0 |       0.1472 ns |     0.0587 ns |      0.1013 ns |       0.1120 ns | 0.000 |       - |      - |         - |        0.00 |
|   Segment |      0 |      13.7178 ns |     0.4738 ns |      1.3364 ns |      13.2508 ns | 0.000 |       - |      - |         - |        0.00 |
|           |        |                 |               |                |                 |       |         |        |           |             |
|      Skip |      1 | 175,118.9780 ns | 5,931.9158 ns | 16,924.0895 ns | 171,513.3057 ns | 1.000 | 12.9395 | 0.9766 |   82566 B |        1.00 |
| BlockCopy |      1 |     792.9510 ns |    31.1743 ns |     91.4287 ns |     778.0930 ns | 0.005 |  2.6102 | 0.1373 |   16456 B |        0.20 |
|   Segment |      1 |      14.3662 ns |     0.5083 ns |      1.4086 ns |      14.0977 ns | 0.000 |       - |      - |         - |        0.00 |
|           |        |                 |               |                |                 |       |         |        |           |             |
|      Skip |   1024 | 164,130.9174 ns | 4,012.2425 ns | 11,703.8997 ns | 162,051.8921 ns | 1.000 |  7.5684 | 0.4883 |   48718 B |        1.00 |
| BlockCopy |   1024 |     796.9357 ns |    36.3113 ns |    106.4947 ns |     779.0838 ns | 0.005 |  2.4509 | 0.1163 |   15432 B |        0.32 |
|   Segment |   1024 |      14.1748 ns |     0.7904 ns |      2.3180 ns |      13.6365 ns | 0.000 |       - |      - |         - |        0.00 |
|           |        |                 |               |                |                 |       |         |        |           |             |
|      Skip |  16384 |  41,364.4897 ns | 1,298.4945 ns |  3,746.4536 ns |  40,894.0216 ns | 1.000 |       - |      - |     305 B |        1.00 |
| BlockCopy |  16384 |      13.9454 ns |     0.4991 ns |      1.4637 ns |      13.7183 ns | 0.000 |  0.0076 |      - |      48 B |        0.16 |
|   Segment |  16384 |      12.3645 ns |     0.4836 ns |      1.3874 ns |      12.0102 ns | 0.000 |       - |      - |         - |        0.00 |