[Perf] Linux/arm64: 17 Improvements on 6/25/2026 12:43:10 AM +00:00

### Run Information

Name | Value
-- | --
Architecture | arm64
OS | azurelinux 3.0
Queue | CobaltAzureLinux
Baseline | [9c1fdaea7e4595785db31a5a219f66fb7d2a4ec1](https://github.com/dotnet/runtime/commit/9c1fdaea7e4595785db31a5a219f66fb7d2a4ec1)
Compare | [818cfd5edcda78ac3eb201af392fd301ab9ad46b](https://github.com/dotnet/runtime/commit/818cfd5edcda78ac3eb201af392fd301ab9ad46b)
Diff | [Diff](https://github.com/dotnet/runtime/compare/9c1fdaea7e4595785db31a5a219f66fb7d2a4ec1...818cfd5edcda78ac3eb201af392fd301ab9ad46b)
Configs | CompilationMode:tiered, R2RType:r2r_interpreter, RunKind:micro

### Improvements in System.Text.Json.Tests.Perf_Strings

Benchmark | Baseline | Test | Test/Base | Test Quality | Edge Detector | Baseline IR | Compare IR | IR Ratio
-- | -- | -- | -- | -- | -- | -- | -- | --
|

• [WriteStringsUtf8 - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config Graph]()

| 110.41 ms | 40.69 ms | 0.37 | 0.13 | False | | |
|

• [WriteStringsUtf8 - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config Graph]()

| 109.86 ms | 45.42 ms | 0.41 | 0.18 | False | | |
|

• [WriteStringsUtf8 - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config Graph]()

| 111.47 ms | 46.21 ms | 0.41 | 0.10 | False | | |
|

• [WriteStringsUtf8 - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config Graph]()

| 111.10 ms | 46.32 ms | 0.42 | 0.14 | False | | |
|

• [WriteStringsUtf16 - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config Graph]()

| 111.68 ms | 49.18 ms | 0.44 | 0.12 | False | | |
|

• [WriteStringsUtf16 - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config Graph]()

| 111.66 ms | 49.43 ms | 0.44 | 0.11 | False | | |
|

• [WriteStringsUtf16 - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config Graph]()

| 112.39 ms | 49.96 ms | 0.44 | 0.10 | False | | |
|

• [WriteStringsUtf16 - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config Graph]()

| 112.01 ms | 50.17 ms | 0.45 | 0.13 | False | | |
|

• [WriteStringsUtf16 - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config Graph]()

| 17.42 ms | 15.04 ms | 0.86 | 0.17 | False | | |
|

• [WriteStringsUtf16 - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config Graph]()

| 18.23 ms | 16.00 ms | 0.88 | 0.13 | False | | |
|

• [WriteStringsUtf16 - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config Graph]()

| 17.39 ms | 15.36 ms | 0.88 | 0.12 | False | | |
|

• [WriteStringsUtf8 - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config Graph]()

| 12.57 ms | 11.42 ms | 0.91 | 0.10 | False | | |
|

• [WriteStringsUtf8 - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config Graph]()

| 11.63 ms | 10.63 ms | 0.91 | 0.12 | False | | |
|

• [WriteStringsUtf8 - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config Graph]()

| 11.65 ms | 10.69 ms | 0.92 | 0.11 | False | | |
|

• [WriteStringsUtf16 - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config Graph]()

| 8.06 ms | 7.43 ms | 0.92 | 0.16 | False | | |
|

• [WriteStringsUtf8 - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config Graph]()

| 12.24 ms | 11.36 ms | 0.93 | 0.13 | False | | |
|

• [WriteStringsUtf16 - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config Graph]()

| 7.56 ms | 7.11 ms | 0.94 | 0.15 | False | | |

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[Test Report]()

### Repro
General Docs link: https://github.com/dotnet/performance/blob/main/docs/benchmarking-workflow-dotnet-runtime.md

```cmd
git clone https://github.com/dotnet/performance.git
py .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Text.Json.Tests.Perf_Strings*'
```

### System.Text.Json.Tests.Perf_Strings.WriteStringsUtf8(Formatted: False, SkipValidation: False, Escaped: AllEscaped)

#### ETL Files

#### Histogram

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### System.Text.Json.Tests.Perf_Strings.WriteStringsUtf8(Formatted: False, SkipValidation: True, Escaped: AllEscaped)

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### System.Text.Json.Tests.Perf_Strings.WriteStringsUtf8(Formatted: True, SkipValidation: True, Escaped: AllEscaped)

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### System.Text.Json.Tests.Perf_Strings.WriteStringsUtf8(Formatted: True, SkipValidation: False, Escaped: AllEscaped)

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### System.Text.Json.Tests.Perf_Strings.WriteStringsUtf16(Formatted: False, SkipValidation: False, Escaped: AllEscaped)

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### System.Text.Json.Tests.Perf_Strings.WriteStringsUtf16(Formatted: False, SkipValidation: True, Escaped: AllEscaped)

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### System.Text.Json.Tests.Perf_Strings.WriteStringsUtf16(Formatted: True, SkipValidation: False, Escaped: AllEscaped)

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### System.Text.Json.Tests.Perf_Strings.WriteStringsUtf16(Formatted: True, SkipValidation: True, Escaped: AllEscaped)

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### System.Text.Json.Tests.Perf_Strings.WriteStringsUtf16(Formatted: False, SkipValidation: True, Escaped: OneEscaped)

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### System.Text.Json.Tests.Perf_Strings.WriteStringsUtf16(Formatted: True, SkipValidation: False, Escaped: OneEscaped)

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### System.Text.Json.Tests.Perf_Strings.WriteStringsUtf16(Formatted: False, SkipValidation: False, Escaped: OneEscaped)

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### System.Text.Json.Tests.Perf_Strings.WriteStringsUtf8(Formatted: True, SkipValidation: True, Escaped: OneEscaped)

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### System.Text.Json.Tests.Perf_Strings.WriteStringsUtf8(Formatted: False, SkipValidation: True, Escaped: OneEscaped)

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### System.Text.Json.Tests.Perf_Strings.WriteStringsUtf8(Formatted: False, SkipValidation: False, Escaped: OneEscaped)

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### System.Text.Json.Tests.Perf_Strings.WriteStringsUtf16(Formatted: True, SkipValidation: True, Escaped: NoneEscaped)

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### System.Text.Json.Tests.Perf_Strings.WriteStringsUtf8(Formatted: True, SkipValidation: False, Escaped: OneEscaped)

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### System.Text.Json.Tests.Perf_Strings.WriteStringsUtf16(Formatted: False, SkipValidation: True, Escaped: NoneEscaped)

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### Docs

[Profiling workflow for dotnet/runtime repository](https://github.com/dotnet/performance/blob/master/docs/profiling-workflow-dotnet-runtime.md)
[Benchmarking workflow for dotnet/runtime repository](https://github.com/dotnet/performance/blob/master/docs/benchmarking-workflow-dotnet-runtime.md)

Start with the linked benchmark source, src/benchmarks/micro/libraries/System.Text.Json/Utf8JsonWriter/Perf.Strings.cs, and compare the baseline and test runs for the listed WriteStringsUtf8 and WriteStringsUtf16 cases. The issue reports improvements rather than a requested change, so done requires triage to identify a concrete, reproducible action or close it as informational.

Written by the indexing model from the issue text.