[Perf] Windows/x64: 3 Regressions on 7/27/2026 11:29:43 AM +00:00

### Run Information

Name | Value
-- | --
Architecture | x64
OS | Windows 10.0.22631
Queue | ViperWindows
Baseline | [ca073c0866e1504313b43781c209f7f680d0ecb3](https://github.com/dotnet/runtime/commit/ca073c0866e1504313b43781c209f7f680d0ecb3)
Compare | [da6081391e5d3227e462c082b345af8720db05c1](https://github.com/dotnet/runtime/commit/da6081391e5d3227e462c082b345af8720db05c1)
Diff | [Diff](https://github.com/dotnet/runtime/compare/ca073c0866e1504313b43781c209f7f680d0ecb3...da6081391e5d3227e462c082b345af8720db05c1)
Configs | CompilationMode:tiered, RunKind:micro

### Regressions in System.Numerics.Tests.Perf_BigInteger

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

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

| 5.17 ns | 6.36 ns | 1.23 | 0.02 | 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.Numerics.Tests.Perf_BigInteger*'
```

### System.Numerics.Tests.Perf_BigInteger.Equals(arguments: 259 bytes, Same)

#### 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 | [2aa2ce008a33a25ac77f4f340b628e135b94087f](https://github.com/dotnet/runtime/commit/2aa2ce008a33a25ac77f4f340b628e135b94087f)
Compare | [da6081391e5d3227e462c082b345af8720db05c1](https://github.com/dotnet/runtime/commit/da6081391e5d3227e462c082b345af8720db05c1)
Diff | [Diff](https://github.com/dotnet/runtime/compare/2aa2ce008a33a25ac77f4f340b628e135b94087f...da6081391e5d3227e462c082b345af8720db05c1)
Configs | CompilationMode:tiered, RunKind:micro

### Regressions in System.IO.Tests.Perf_StreamWriter

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

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

| 78.95 ms | 83.90 ms | 1.06 | 0.01 | 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.IO.Tests.Perf_StreamWriter*'
```

### System.IO.Tests.Perf_StreamWriter.WriteString(writeLength: 2)

#### 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 | [2aa2ce008a33a25ac77f4f340b628e135b94087f](https://github.com/dotnet/runtime/commit/2aa2ce008a33a25ac77f4f340b628e135b94087f)
Compare | [da6081391e5d3227e462c082b345af8720db05c1](https://github.com/dotnet/runtime/commit/da6081391e5d3227e462c082b345af8720db05c1)
Diff | [Diff](https://github.com/dotnet/runtime/compare/2aa2ce008a33a25ac77f4f340b628e135b94087f...da6081391e5d3227e462c082b345af8720db05c1)
Configs | CompilationMode:tiered, RunKind:micro

### Regressions in System.Buffers.Tests.RentReturnArrayPoolTests<Byte>

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

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

| 1.32 μs | 1.54 μs | 1.17 | 0.45 | 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.Tests.RentReturnArrayPoolTests*'
```

### System.Buffers.Tests.RentReturnArrayPoolTests<Byte>.ProducerConsumer(RentalSize: 4096, ManipulateArray: True, Async: False, UseSharedPool: False)

#### 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)