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1. What Are Benchmarks?

A benchmark is a controlled, repeatable experiment that measures the performance characteristics of a piece of code.

A good benchmark answers questions like:

• How long does this method take to run?
• How many CPU cycles does this algorithm consume?
• What is the memory allocation?
• How does performance change with input sizes?
• Does version A outperform version B?

✔ Benchmarking Focuses On:

• Execution time (ns, µs, ms)
• Memory allocations
• Throughput (operations/sec)
• JIT/Runtime behavior
• GC impact
• Branch prediction & micro-architectural effects

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2. Why Benchmarking Is Needed?

Because developers guess, but numbers never lie.

Benchmarking helps you:

✔ 1. Compare two algorithms

Example:
List<T> vs Span<T> vs Array.

✔ 2. Detect regressions

Upgrading from .NET 6 → 8 → 9 may change performance.

✔ 3. Understand JIT optimizations

• inlining
• bounds check elimination
• loop unrolling

✔ 4. Optimize hot paths

Critical in:

• microservices
• high-frequency trading
• game engines
• telemetry pipelines

✔ 5. Avoid “fake performance perception”

Normal debugging/profiling distorts real performance.

A benchmark runs code:

• multiple times
• warms up the JIT
• isolates noise
• prints statistically correct data

That is why BenchmarkDotNet exists.

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3. What Is BenchmarkDotNet?

BenchmarkDotNet is an open-source, industry-standard benchmarking framework for .NET created by .NET performance experts.

It is used by:

• Microsoft .NET runtime team
• JetBrains
• StackOverflow
• Elastic
• Cloudflare
• Prof. Andrey Akinshin (GC expert)

✔ What it does?

It automatically:

• Compiles benchmarks in RELEASE mode
• Runs warm-ups
• Runs in-process or in a separate process
• Produces statistically accurate reports
• Removes JIT & GC noise
• Exports results to HTML/Markdown/CSV
• Supports hardware counters (Perf Counters, PMCs)
• Works on Windows, Linux, macOS

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4. Key Features of BenchmarkDotNet (2025)

✔ Full cross-platform (.NET 6–9)

Supports Windows/Linux/macOS, ARM64, Docker.

✔ Automatic Environment Info

• CPU name
• OS version
• .NET runtime version
• Turbo boost, frequency
• GC mode
• Memory info

✔ Accurate measurements

• Warmup
• Pilot execution
• Auto iteration
• Outlier removal
• Confidence intervals
• Standard deviation

✔ Memory diagnostics

• Allocations per operation
• GC pressure

✔ Hardware counters

Supports:

• Branch misses
• Cache hits/misses
• Instruction count
• CPU cycles

✔ Export formats

• HTML
• Markdown
• JSON
• CSV
• GitHub-flavored tables

✔ Baseline comparison

Easy before/after performance comparison.

✔ Parameterized benchmarks

Run inputs like 10, 100, 1000 automatically.

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5. Installing BenchmarkDotNet (Latest Version 2025)

Run:

dotnet add package BenchmarkDotNet

Verify:

dotnet list package
Code language: PHP (php)

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6. Basic Workflow of BenchmarkDotNet

Step 1 — Create a console app

dotnet new console -n BenchmarksDemo
cd BenchmarksDemo
Code language: JavaScript (javascript)

Step 2 — Install BenchmarkDotNet

dotnet add package BenchmarkDotNet

Step 3 — Create Benchmark class

using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Running;

public class StringBenchmarks
{
    [Benchmark]
    public string ConcatPlus() => "Hello" + "World";

    [Benchmark]
    public string ConcatJoin() => string.Join("", "Hello", "World");

    [Benchmark]
    public string ConcatStringBuilder()
    {
        var sb = new System.Text.StringBuilder();
        sb.Append("Hello");
        sb.Append("World");
        return sb.ToString();
    }
}
Code language: PHP (php)

Step 4 — Run benchmarks

BenchmarkRunner.Run<StringBenchmarks>();
Code language: HTML, XML (xml)

Step 5 — Build & Run (Always RELEASE mode)

dotnet run -c Release

BenchmarkDotNet automatically:

• emits code
• runs warmups
• executes millions of iterations
• prints HTML reports

Output example:

|            Method |      Mean |    Error |   StdDev |   Allocated |
|------------------ |----------:|---------:|---------:|------------:|
|       ConcatPlus  |  12.25 ns | 0.20 ns  | 0.18 ns  |           - |
|       ConcatJoin  |  23.12 ns | 0.18 ns  | 0.17 ns  |         24 B|
| ConcatStringBuilder | 45.55 ns | 0.55 ns | 0.50 ns |        120 B|
Code language: JavaScript (javascript)

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7. BenchmarkDotNet Commands / Attributes (Latest 2025 Guide)

✔ [Benchmark]

Marks a benchmark method.

✔ [MemoryDiagnoser]

Adds memory usage & allocations.

✔ [SimpleJob]

Custom job configuration.

Example:

[SimpleJob(RuntimeMoniker.Net80)]
Code language: JSON / JSON with Comments (json)

✔ [Params]

Parameterized benchmark inputs.

[Params(10, 100, 1000)]
public int Size;
Code language: CSS (css)

✔ [BenchmarkCategory]

Categorize benchmarks.

✔ [IterationCount]

Controls iterations.

✔ [WarmupCount]

Warm-up run count.

✔ [Baseline]

Mark comparison baseline.

✔ [RankColumn]

Ranks the results.

✔ [Orderer]

Sort results by speed.

✔ [HardwareCounters]

Enable hardware-level CPU counters.

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8. Practical Examples (Beginner → Advanced)

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⭐ Example 1: Basic Benchmark

using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Running;

[MemoryDiagnoser]
public class MathBenchmark
{
    [Benchmark]
    public double SqrtFast() => Math.Sqrt(12345);

    [Benchmark]
    public double Pow() => Math.Pow(12345, 0.5);
}

public class Program
{
    public static void Main() => BenchmarkRunner.Run<MathBenchmark>();
}
Code language: PHP (php)

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⭐ Example 2: Compare two versions (Baseline)

[MemoryDiagnoser]
public class LoopBench
{
    [Benchmark(Baseline = true)]
    public int ForLoop()
    {
        int sum = 0;
        for (int i = 0; i < 1000; i++) sum += i;
        return sum;
    }

    [Benchmark]
    public int LinqSum() => Enumerable.Range(0, 1000).Sum();
}
Code language: PHP (php)

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⭐ Example 3: Parameterized Benchmark

[MemoryDiagnoser]
public class ArrayBench
{
    [Params(10, 100, 1000)]
    public int N;

    [Benchmark]
    public int[] AllocateArray() => new int[N];
}
Code language: PHP (php)

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⭐ Example 4: Benchmark async/await

[MemoryDiagnoser]
public class AsyncBench
{
    [Benchmark]
    public async Task Delay() => await Task.Delay(10);
}
Code language: PHP (php)

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⭐ Example 5: Benchmark with hardware counters

[HardwareCounters(HardwareCounter.CacheMisses, HardwareCounter.BranchMispredictions)]
[MemoryDiagnoser]
public class CpuBench
{
    [Benchmark]
    public void Work()
    {
        long x = 0;
        for (int i = 0; i < 1_000_000; i++) x += i;
    }
}
Code language: PHP (php)

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9. Use Cases of BenchmarkDotNet

✔ Algorithm comparison

• sorting
• searching
• hashing
• JSON serialization

✔ Testing performance regressions

Used in CI pipelines.

✔ Microservices / API optimizations

• cold start time
• deserialization
• routing

✔ Game engines

Unity developers use it for hot paths.

✔ Memory optimization

Detect unnecessary allocations.

✔ Comparing new .NET versions

.NET 6 → .NET 7 → .NET 8 → .NET 9 improvements.

✔ Database client performance

EF Core, Dapper, MongoDB drivers.

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10. Best Practices (2025 Edition)

✔ Always run benchmarks in Release mode

Debug mode distorts everything.

✔ Don’t benchmark using IDE run button

Must use:
dotnet run -c Release

✔ Don’t benchmark noisy code

Avoid:

• network I/O
• disk
• random sleeps
• unpredictable cache

✔ Avoid too small methods

JIT may inline them.

Use:

[MethodImpl(MethodImplOptions.NoInlining)]
Code language: JSON / JSON with Comments (json)

✔ Use MemoryDiagnoser

Memory is often more important than CPU.

✔ Always isolate variables

Use parameters instead of manual loops.

✔ Avoid reading/writing files

Use mocks for consistency.

✔ Use baselines

Comparisons are clearer.

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11. CI/CD Integration (2025)

BenchmarkDotNet supports running inside:

• GitHub Actions
• GitLab CI
• Azure DevOps
• Jenkins
• TeamCity

Use command:

--exporters json
--filter *BenchmarkName*

Example GitHub Action:

- name: Run Benchmarks
  run: dotnet run -c Release -- --filter *MyBench*

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12. BenchmarkDotNet Architecture (Simplified)

1. Generate auto code
2. Compile project separately
3. Launch a new process
4. Warm-up phase
5. Pilot phase
6. Targeted runs
7. Statistical analysis
8. HTML export
9. Store results in /BenchmarkDotNet.Artifacts/

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13. Additional Useful Attributes (2025)

Attribute	Description
[MinColumn, MaxColumn]	Show min/max results
[StdDevColumn]	Standard deviation
[Orderer]	Sort results by speed
[RankColumn]	Rank results
[ThreadingDiagnoser]	Thread usage
[ConcurrencyVisualizer]	Thread visualization
[EtwProfiler]	ETW profiler
[DisassemblyDiagnoser]	JIT ASM output

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14. Advanced: Disassembly (JIT ASM)

[DisassemblyDiagnoser(printSource: true)]
public class Bench
{
    [Benchmark]
    public int Add() => 1 + 2;
}
Code language: PHP (php)

Run:

dotnet run -c Release -- --disasm

This shows machine instructions.

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15. Summary

You now have the most advanced, end-to-end, complete, updated (2025) tutorial for:

✔ Benchmarking fundamentals
✔ BenchmarkDotNet features
✔ Install instructions
✔ Attributes list
✔ Commands
✔ CI/CD Integration
✔ Best practices
✔ Baseline comparisons
✔ Memory and CPU diagnostics
✔ Examples from beginner to expert

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Just tell me!