[Perf] Windows/x64: 4 Improvements on 7/6/2026 7:38:21 AM +00:00

### Run Information

Name | Value
-- | --
Architecture | x64
OS | Windows 10.0.22631
Queue | ViperWindows
Baseline | [8f365c934088b8ae21a4dfce8073da0d3eb22a54](https://github.com/dotnet/runtime/commit/8f365c934088b8ae21a4dfce8073da0d3eb22a54)
Compare | [c473d80e67a0e090fa4a3e67fbc5bc9d122b172a](https://github.com/dotnet/runtime/commit/c473d80e67a0e090fa4a3e67fbc5bc9d122b172a)
Diff | [Diff](https://github.com/dotnet/runtime/compare/8f365c934088b8ae21a4dfce8073da0d3eb22a54...c473d80e67a0e090fa4a3e67fbc5bc9d122b172a)
Configs | CompilationMode:tiered, RunKind:micro

### Improvements in System.Numerics.Tests.Perf_VectorConvert

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

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

| 546.90 ns | 434.36 ns | 0.79 | 0.04 | False | | |
|

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

| 547.12 ns | 434.67 ns | 0.79 | 0.07 | False | | |

![graph]()
![graph]()
[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.Numerics.Tests.Perf_VectorConvert*'
```

### System.Numerics.Tests.Perf_VectorConvert.Widen_short

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Numerics.Tests.Perf_VectorConvert.Widen_byte

#### ETL Files

#### Histogram

#### JIT Disasms

### 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)

---

### Run Information

Name | Value
-- | --
Architecture | x64
OS | Windows 10.0.22631
Queue | ViperWindows
Baseline | [8f365c934088b8ae21a4dfce8073da0d3eb22a54](https://github.com/dotnet/runtime/commit/8f365c934088b8ae21a4dfce8073da0d3eb22a54)
Compare | [c473d80e67a0e090fa4a3e67fbc5bc9d122b172a](https://github.com/dotnet/runtime/commit/c473d80e67a0e090fa4a3e67fbc5bc9d122b172a)
Diff | [Diff](https://github.com/dotnet/runtime/compare/8f365c934088b8ae21a4dfce8073da0d3eb22a54...c473d80e67a0e090fa4a3e67fbc5bc9d122b172a)
Configs | CompilationMode:tiered, RunKind:micro

### Improvements in System.Text.Json.Serialization.Tests.WriteJson<Hashtable>

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

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

| 5.93 μs | 5.04 μs | 0.85 | 0.19 | False | | |

![graph]()
[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.Serialization.Tests.WriteJson*'
```

### System.Text.Json.Serialization.Tests.WriteJson<Hashtable>.SerializeToString(Mode: Reflection)

#### ETL Files

#### Histogram

#### JIT Disasms

### 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)

---

### Run Information

Name | Value
-- | --
Architecture | x64
OS | Windows 10.0.22631
Queue | ViperWindows
Baseline | [8f365c934088b8ae21a4dfce8073da0d3eb22a54](https://github.com/dotnet/runtime/commit/8f365c934088b8ae21a4dfce8073da0d3eb22a54)
Compare | [c473d80e67a0e090fa4a3e67fbc5bc9d122b172a](https://github.com/dotnet/runtime/commit/c473d80e67a0e090fa4a3e67fbc5bc9d122b172a)
Diff | [Diff](https://github.com/dotnet/runtime/compare/8f365c934088b8ae21a4dfce8073da0d3eb22a54...c473d80e67a0e090fa4a3e67fbc5bc9d122b172a)
Configs | CompilationMode:tiered, RunKind:micro

### Improvements in System.Buffers.Binary.Tests.BinaryReadAndWriteTests

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

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

| 547.38 ns | 411.57 ns | 0.75 | 0.19 | False | | |

![graph]()
[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.Buffers.Binary.Tests.BinaryReadAndWriteTests*'
```

### System.Buffers.Binary.Tests.BinaryReadAndWriteTests.MeasureReverseEndianness

#### ETL Files

#### Histogram

#### JIT Disasms

### 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 benchmark sources at Perf_VectorConvert.cs, WriteJson.cs, and BinaryReadAndWriteTests.cs, then run the listed benchmarks with benchmarks_ci.py using the provided filters. Compare the Windows x64 results with the linked baseline and report whether the measured improvements are expected; the issue does not define a code change or a more specific completion condition.

Written by the indexing model from the issue text.