[Perf] Linux/arm64: 2 Improvements on 8/21/2026 2:45:13 AM +00:00

### Run Information

Name | Value
-- | --
Architecture | arm64
OS | azurelinux 3.0
Queue | CobaltAzureLinux
Baseline | [be1c680101458a735200e68a74460919be249315](https://github.com/dotnet/runtime/commit/be1c680101458a735200e68a74460919be249315)
Compare | [76c60b960a2daa412c44a5061abf66f3286f6a92](https://github.com/dotnet/runtime/commit/76c60b960a2daa412c44a5061abf66f3286f6a92)
Diff | [Diff](https://github.com/dotnet/runtime/compare/be1c680101458a735200e68a74460919be249315...76c60b960a2daa412c44a5061abf66f3286f6a92)
Configs | CompilationMode:tiered, RunKind:micro

### Improvements in System.Collections.CopyTo<String>

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

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

| 972.45 ns | 506.22 ns | 0.52 | 0.69 | False | | |
|

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

| 615.24 ns | 391.99 ns | 0.64 | 0.67 | 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.Collections.CopyTo*'
```

### System.Collections.CopyTo<String>.Memory(Size: 2048)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Collections.CopyTo<String>.List(Size: 2048)

#### 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 linked System.Collections.CopyTo benchmark source in dotnet/performance/src/benchmarks/micro/libraries/System.Collections/CopyTo.cs and compare the listed baseline and test commits. Run the provided benchmarks_ci.py command with the System.Collections.CopyTo filter, then inspect the linked report and graphs. Done means the improvement is understood and any required runtime or benchmark follow-up is identified.

Written by the indexing model from the issue text.