BenchD

Deployment: https://userfrom1995.github.io/benchd/

BenchD is a browser-based CPU benchmark that runs fully on the client, with no backend and no telemetry.

• Runs fully on the client
• Uses WASM + Web Workers + WebCrypto
• No backend and no telemetry
• Exports raw benchmark results as JSON

What BenchD Tests

• FP32 and FP64 compute throughput using independent accumulator streams
• Integer compute throughput
• SIMD compute throughput
• WASM memory bandwidth
• Random-walk latency at fixed working-set sizes: 32KB, 256KB, 8MB, and 64MB
• Branch prediction behavior
• Cryptography (AES-GCM, SHA-256)
• Compression and decompression throughput
• Multi-core scaling
• WASM loop throughput

The goal is to provide a practical browser-side CPU performance snapshot with no server dependency.

Measurement Notes

BenchD is a browser benchmark, not a native hardware profiler. Results are useful for comparing browser-side execution on the same browser/device class, but they are not directly comparable to native tools.

• WASM loop throughput is not CPU clock speed. Browsers do not expose real CPU frequency, hardware counters, or OS power telemetry. BenchD reports this as GOPS instead of GHz.
• Random-walk latency is labeled by working-set size. The app no longer labels fixed buffers as L1/L2/L3/RAM because cache sizes differ by CPU, core type, and device. A 32KB test is always a 32KB random walk; whether that maps to L1 depends on the machine.
• Memory bandwidth is measured inside WASM memory. The benchmark uses an internal WASM buffer so the result is less affected by JS-to-WASM typed-array copy overhead.
• Crypto uses WebCrypto. AES-GCM and SHA-256 are measured through browser WebCrypto APIs, which may use browser or platform acceleration.
• Raw JSON export is available after a run. The export includes the score, raw category results, window samples, browser metadata, worker count, SharedArrayBuffer availability, and cross-origin isolation state.

Beta Notice

This is a beta release of the project.

Some benchmark tests may not yet behave exactly as intended, and there are known bugs across:

• Benchmark/test logic
• Rust/WASM kernels
• Edge-case behavior in some categories
• Cross-browser variance

These issues will be fixed in subsequent releases.

Contributions

Contributions are welcome.

• Open an issue for bugs or feature ideas
• Open a pull request for fixes/improvements
• Keep changes focused and tested when possible

Run Locally

cd wasm
wasm-pack build --target web --release --no-opt

cd ..
npx -y serve . -p 4200 --no-clipboard

Open http://localhost:4200.

Build Notes

• wasm/pkg should be committed for deployment.
• wasm/target should not be committed.
• The wasm build uses rand 0.9 with getrandom 0.3 configured for the browser wasm_js backend.
• The wasm target config enables simd128; rebuild wasm/pkg after changing Rust kernels.
• If results look stale, unregister the service worker in DevTools and hard refresh.

License

This project is released under a custom proprietary license.

• Non-commercial and educational use is allowed with attribution
• Commercial/profit/manufacturing use requires prior written permission
• See LICENSE for full terms