[Perf] Linux/arm64: 27 Improvements on 8/11/2026 11:24:58 PM +00:00

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#77,889 opened on Aug 13, 2026 2 comments 0 reactions 0 assignees View on GitHub

ampere arch-arm64 branch-refs/heads/main compilationmode-tiered kind-micro os-linux perf-improvement runkind-micro runtime-coreclr untriaged

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Stars: 10
Forks: 8
PR merge metrics: PR metrics pending

Description

### Run Information

Name | Value
-- | --
Architecture | arm64
OS | ubuntu 22.04
Queue | AmpereUbuntu
Baseline | [60108ba66eb7d1d12f595480091b4ad80a24b172](https://github.com/dotnet/runtime/commit/60108ba66eb7d1d12f595480091b4ad80a24b172)
Compare | [19a2d977ed14ff9ab7417519f0257b3b296a82f4](https://github.com/dotnet/runtime/commit/19a2d977ed14ff9ab7417519f0257b3b296a82f4)
Diff | [Diff](https://github.com/dotnet/runtime/compare/60108ba66eb7d1d12f595480091b4ad80a24b172...19a2d977ed14ff9ab7417519f0257b3b296a82f4)
Configs | CompilationMode:tiered, RunKind:micro

### Improvements in System.Threading.Channels.Tests.SpscUnboundedChannelPerfTests

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

[TryWriteThenTryRead - Duration of single invocation]()
[ADX - Test Multi Config Graph]()

| 49.50 ns | 34.39 ns | 0.69 | 0.19 | False | | |
|

[WriteAsyncThenReadAsync - Duration of single invocation]()
[ADX - Test Multi Config Graph]()

| 71.53 ns | 54.86 ns | 0.77 | 0.05 | False | | |
|

[ReadAsyncThenWriteAsync - Duration of single invocation]()
[ADX - Test Multi Config Graph]()

| 118.83 ns | 96.05 ns | 0.81 | 0.24 | False | | |

![graph]()
![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
python3 .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Threading.Channels.Tests.SpscUnboundedChannelPerfTests*'
```

### System.Threading.Channels.Tests.SpscUnboundedChannelPerfTests.TryWriteThenTryRead

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Threading.Channels.Tests.SpscUnboundedChannelPerfTests.WriteAsyncThenReadAsync

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Threading.Channels.Tests.SpscUnboundedChannelPerfTests.ReadAsyncThenWriteAsync

#### 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

### Improvements in System.ConsoleTests.Perf_Console

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

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

| 29.79 ns | 20.24 ns | 0.68 | 0.34 | False | | |
|

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

| 29.65 ns | 20.29 ns | 0.68 | 0.31 | False | | |
|

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

| 93.64 ns | 70.03 ns | 0.75 | 0.22 | False | | |

![graph]()
![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
python3 .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.ConsoleTests.Perf_Console*'
```

### System.ConsoleTests.Perf_Console.BackgroundColor

#### ETL Files

#### Histogram

#### JIT Disasms

### System.ConsoleTests.Perf_Console.ForegroundColor

#### ETL Files

#### Histogram

#### JIT Disasms

### System.ConsoleTests.Perf_Console.ResetColor

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Improvements in System.Threading.Channels.Tests.UnboundedChannelPerfTests

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

[TryWriteThenTryRead - Duration of single invocation]()
[ADX - Test Multi Config Graph]()

| 62.01 ns | 45.32 ns | 0.73 | 0.26 | False | | |
|

[WriteAsyncThenReadAsync - Duration of single invocation]()
[ADX - Test Multi Config Graph]()

| 77.03 ns | 59.83 ns | 0.78 | 0.05 | 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
python3 .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Threading.Channels.Tests.UnboundedChannelPerfTests*'
```

### System.Threading.Channels.Tests.UnboundedChannelPerfTests.TryWriteThenTryRead

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Threading.Channels.Tests.UnboundedChannelPerfTests.WriteAsyncThenReadAsync

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Improvements in System.Tests.Perf_String

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

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

| 27.31 ns | 22.91 ns | 0.84 | 0.07 | False | | |
|

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

| 12.98 ns | 11.46 ns | 0.88 | 0.34 | 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
python3 .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Tests.Perf_String*'
```

### System.Tests.Perf_String.GetChars(size: 100)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Tests.Perf_String.PadLeft(n: 18)

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Improvements in System.Threading.Channels.Tests.BoundedChannelPerfTests

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

[WriteAsyncThenReadAsync - Duration of single invocation]()
[ADX - Test Multi Config Graph]()

| 99.58 ns | 73.76 ns | 0.74 | 0.08 | False | | |
|

[TryWriteThenTryRead - Duration of single invocation]()
[ADX - Test Multi Config Graph]()

| 81.15 ns | 62.07 ns | 0.76 | 0.19 | 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
python3 .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Threading.Channels.Tests.BoundedChannelPerfTests*'
```

### System.Threading.Channels.Tests.BoundedChannelPerfTests.WriteAsyncThenReadAsync

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Threading.Channels.Tests.BoundedChannelPerfTests.TryWriteThenTryRead

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Improvements in System.Threading.Tests.Perf_Monitor

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

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

| 25.89 ns | 17.92 ns | 0.69 | 0.40 | False | | |
|

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

| 26.32 ns | 18.41 ns | 0.70 | 0.40 | 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
python3 .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Threading.Tests.Perf_Monitor*'
```

### System.Threading.Tests.Perf_Monitor.TryEnterExit

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Threading.Tests.Perf_Monitor.EnterExit

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Improvements in System.Collections.Concurrent.Count<Int32>

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

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

| 2.16 μs | 1.52 μs | 0.71 | 0.40 | False | | |
|

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

| 59.56 ns | 44.23 ns | 0.74 | 0.19 | 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
python3 .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Collections.Concurrent.Count*'
```

### System.Collections.Concurrent.Count<Int32>.Dictionary(Size: 512)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Collections.Concurrent.Count<Int32>.Bag(Size: 512)

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Improvements in System.Collections.Concurrent.Count<String>

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

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

| 2.12 μs | 1.53 μs | 0.72 | 0.42 | False | | |
|

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

| 59.67 ns | 43.67 ns | 0.73 | 0.22 | 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
python3 .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Collections.Concurrent.Count*'
```

### System.Collections.Concurrent.Count<String>.Dictionary(Size: 512)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Collections.Concurrent.Count<String>.Bag(Size: 512)

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Improvements in System.Collections.IndexerSet<Int32>

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

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

| 20.91 μs | 14.80 μs | 0.71 | 0.13 | 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
python3 .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Collections.IndexerSet*'
```

### System.Collections.IndexerSet<Int32>.ConcurrentDictionary(Size: 512)

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Improvements in System.Tests.Perf_GC<Char>

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

[AllocateArray - Duration of single invocation]()
[ADX - Test Multi Config Graph]()

| 151.15 ns | 135.86 ns | 0.90 | 0.03 | 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
python3 .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Tests.Perf_GC*'
```

### System.Tests.Perf_GC<Char>.AllocateArray(length: 1000, pinned: False)

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Improvements in System.Collections.Concurrent.IsEmpty<Int32>

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

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

| 2.09 μs | 1.51 μs | 0.72 | 0.37 | 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
python3 .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Collections.Concurrent.IsEmpty*'
```

### System.Collections.Concurrent.IsEmpty<Int32>.Dictionary(Size: 0)

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Improvements in Microsoft.Extensions.Caching.Memory.Tests.MemoryCacheTests

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

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

| 124.39 ns | 108.98 ns | 0.88 | 0.16 | 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
python3 .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'Microsoft.Extensions.Caching.Memory.Tests.MemoryCacheTests*'
```

### Microsoft.Extensions.Caching.Memory.Tests.MemoryCacheTests.SetOverride

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Improvements in System.Memory.Memory<Byte>

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

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

| 57.83 ns | 51.33 ns | 0.89 | 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
python3 .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Memory.Memory*'
```

### System.Memory.Memory<Byte>.ToArray(Size: 512)

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Improvements in System.Text.Tests.Perf_StringBuilder

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

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

| 2.65 μs | 2.43 μs | 0.92 | 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
python3 .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Text.Tests.Perf_StringBuilder*'
```

### System.Text.Tests.Perf_StringBuilder.Append_ValueTypes_Interpolated

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

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

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

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

| 32.18 μs | 24.69 μs | 0.77 | 0.23 | 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
python3 .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Collections.IndexerSet*'
```

### System.Collections.IndexerSet<String>.ConcurrentDictionary(Size: 512)

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

Contributor guide

No contributing guide indexed for this repository

Research direction

Start with the linked benchmark reports and the reproduction command for System.Threading.Channels.Tests.SpscUnboundedChannelPerfTests and System.ConsoleTests.Perf_Console. Read the referenced performance source at src/benchmarks/micro/libraries/System.Console/Perf.Console.cs, then verify the ARM64 Ubuntu 22.04 results. Done is not defined beyond the reported measurements, so triage must first identify an actionable runtime or benchmark change.

Written by the indexing model from the issue text.

Assessment

Tech stack: csharp, linux, python
Domain: performance
Issue type: Bug
Difficulty: 4/5
Estimated time: 3-5 days
Activity status: Quiet
Clarity: Needs clarification
Newbie friendliness: 28/100

[Perf] Linux/arm64: 27 Improvements on 8/11/2026 11:24:58 PM +00:00

Description

Contributor guide

Research direction

Assessment

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