[Perf] Windows/x86: 1 Improvement on 8/7/2026 11:43:54 PM +00:00

### Run Information

Name | Value
-- | --
Architecture | x86
OS | Windows 10.0.22631
Queue | ViperWindows
Baseline | [45fb46d810550207fe12a2b02dabec25f47c71ad](https://github.com/dotnet/runtime/commit/45fb46d810550207fe12a2b02dabec25f47c71ad)
Compare | [a94502c975d011f1a3a4da9755f10fff1a57391d](https://github.com/dotnet/runtime/commit/a94502c975d011f1a3a4da9755f10fff1a57391d)
Diff | [Diff](https://github.com/dotnet/runtime/compare/45fb46d810550207fe12a2b02dabec25f47c71ad...a94502c975d011f1a3a4da9755f10fff1a57391d)
Configs | CompilationMode:tiered, RunKind:micro

### Improvements in System.IO.Tests.Perf_FileStream

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

• [WriteAsync - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config 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.IO.Tests.Perf_FileStream*'
```

### System.IO.Tests.Perf_FileStream.WriteAsync(fileSize: 104857600, userBufferSize: 4096, options: None)

#### 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 System.IO.Tests.Perf_FileStream.WriteAsync benchmark in performance/src/benchmarks/micro/libraries/System.IO.FileSystem/Perf.FileStream.cs at the linked lines, then run the provided benchmarks_ci.py command. Compare the Windows/x86 result with the linked baseline and test commits and inspect the available performance report. Done means the reported improvement is explained and any resulting change is validated by the benchmark.

Written by the indexing model from the issue text.