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StreamBench

What StreamBench is
StreamBench is a free, open-source benchmark for CPU and GPU memory bandwidth plus AI inference on CPU, GPU, and NPU hardware. Memory tests run the Copy, Scale, Add, and Triad STREAM kernels. AI tests report model load time, first-response time, and warm-run tokens per second through Microsoft Foundry Local, LM Studio, or Ollama. Foundry Local supports CPU, GPU, and NPU benchmarking; LM Studio and Ollama do not support NPU tests. The command-line interface displays results and exports JSON or CSV files. Range testing sweeps array sizes and saves consolidated CSV output, while custom profiles and automation are supported. StreamBench runs on Windows, macOS, and Linux, with Windows and macOS binaries in x64 and ARM64 variants. Linux users can use documented launch scripts or build from source. GPU testing uses dynamically loaded OpenCL without a GPU SDK dependency. Saved results may include hardware details and the hostname. The project is limited to single-node benchmarking.
Who it suits
StreamBench suits users comparing modern CPU, GPU, and AI hardware who want visual results, prebuilt binaries, custom profiles, or command-line automation.
What it does well
- Free and open source
- Measures CPU, GPU, and NPU workloads
- JSON and CSV export
- Custom profiles and range testing
- Windows, macOS, and Linux support
What to know first
- Focused on single-node benchmarking
- NPU tests require Foundry Local
- macOS Foundry Local is GPU-only
- Saved files may include hostname
Verdict
StreamBench combines STREAM memory kernels with AI inference timing across major desktop platforms. Backend choice affects available devices, and exported files should be reviewed before sharing.
Facts from StreamBench's own pages
- AI backends
- The AI inference benchmark supports Microsoft Foundry Local, LM Studio, and Ollama. · github.com, 11 Oct 2026
- AI integrations
- It supports Microsoft Foundry Local, LM Studio, and Ollama as AI backends. · github.com, 11 Oct 2026
- AI measurements
- The AI benchmark reports model load time, first-run response time, and warm-run tokens per second. · github.com, 11 Oct 2026
- Array size
- The README recommends using arrays at least four times larger than the largest cache and notes that small sizes can be skewed by cache effects. · github.com, 11 Oct 2026
- Automation
- Range testing can sweep array sizes and save consolidated CSV output. · github.com, 11 Oct 2026
- CLI or automation
- Yes · github.com, 22 Sept 2026
- Custom test profiles
- Yes · github.com, 22 Sept 2026
- Device coverage
- Foundry Local supports CPU, GPU, and NPU benchmarking; LM Studio and Ollama do not support NPU benchmarking. · github.com, 11 Oct 2026
- Downloads
- The project offers prebuilt binaries for Windows and macOS, with x64 and ARM64 variants. · github.com, 11 Oct 2026
- GPU testing
- The GPU memory bandwidth backend uses OpenCL, which the project says is loaded dynamically without a GPU SDK dependency. · github.com, 11 Oct 2026
- Intended users
- The README describes it as aimed at users seeking a quick visual benchmark with prebuilt binaries, GPU coverage, and AI inference comparisons on modern hardware. · github.com, 11 Oct 2026
- Limits
- The project is focused on single-node benchmarking and does not include the MPI support listed for upstream STREAM. · github.com, 11 Oct 2026
- Linux support
- The README documents macOS and Linux launch scripts and says the project can be built from source on Linux. · github.com, 11 Oct 2026
- macOS limitation
- Foundry Local on macOS currently supports GPU mode only, without CPU or NPU device targeting. · github.com, 11 Oct 2026
- Measured AI metrics
- It reports model load time, first-response time, and warm-run tokens per second. · github.com, 11 Oct 2026
- Memory tests
- Its CPU and GPU benchmarks run the Copy, Scale, Add, and Triad STREAM kernels. · github.com, 11 Oct 2026
- NPU limitation
- NPU benchmarking requires Foundry Local; the README says LM Studio and Ollama do not support NPU benchmarking. · github.com, 11 Oct 2026
- Operating systems
- Windows; macOS; Linux · github.com, 22 Sept 2026
- Platforms
- Prebuilt downloads are offered for Windows and macOS, while the project also documents Linux use and source builds. · github.com, 11 Oct 2026
- Privacy
- Saved results and CLI summaries may include hardware details and the hostname, and the project advises reviewing files before sharing them publicly. · github.com, 11 Oct 2026
- Purpose
- StreamBench benchmarks memory bandwidth and AI inference across CPU, GPU, and NPU hardware. · github.com, 11 Oct 2026
- Requirements
- AI benchmarking requires at least one supported AI backend, which the setup script can install. · github.com, 11 Oct 2026
- Result export formats
- JSON; CSV · github.com, 22 Sept 2026
- Results
- The CLI displays benchmark results and can save them in JSON and CSV formats. · github.com, 11 Oct 2026
Where StreamBench stands on Freedom251
- PC Benchmark Software#56 of 73
- PC benchmark tools#58 of 70