2.7 KiB
Benchmarks
Performance and bundle size measurements for nrel-spa, with comparisons to solar-spa.
Bundle Size
Measured from dist/ after pnpm build.
| File | Raw | Gzipped |
|---|---|---|
index.mjs (ESM) |
5.8 KB | 2.0 KB |
index.cjs (CJS) |
6.5 KB | 2.2 KB |
The package also includes lib/spa.cjs (the core algorithm), which adds ~38 KB raw. The full nrel-spa npm pack total is under 100 KB uncompressed.
solar-spa bundles a compiled WASM binary. Total npm pack size is approximately 60 KB gzipped, compared to ~40 KB for nrel-spa.
Throughput
Environment: Node.js v24.6.0, macOS. 200,000 iterations per measurement with a 2,000-iteration warm-up. Test case: New York summer solstice, SPA_ZA_RTS (full rise/set calculation).
| Implementation | ns/call | calls/s |
|---|---|---|
| nrel-spa | 84,497 | 11,835 |
| solar-spa | 45,139 | 22,154 |
solar-spa WASM is 1.5-1.9x faster for sustained throughput. The WASM binary is compiled from the same C source with -O2.
Switching to SPA_ZA (zenith and azimuth only, no rise/set) removes the three-day interpolation step:
| Implementation | Mode | ns/call | calls/s |
|---|---|---|---|
| nrel-spa | SPA_ZA_RTS | 84,497 | 11,835 |
| nrel-spa | SPA_ZA | 9,284 | 107,711 |
| solar-spa | SPA_ZA_RTS | 45,139 | 22,154 |
| solar-spa | SPA_ZA | 6,112 | 163,616 |
SPA_ZA is roughly 9x faster in nrel-spa. Use it when rise/set times are not needed.
When Each Package Fits
| Scenario | Recommendation |
|---|---|
| Serverless, edge workers, middleware | nrel-spa (synchronous, zero init, smaller) |
| Single request in a Node server | nrel-spa (no async overhead) |
| Batch pre-computation (100K+ calls) | solar-spa (1.5-1.9x faster after init) |
| Custom twilight angles | nrel-spa (solar-spa does not support custom zenith angles) |
Methodology
Throughput numbers above come from the manual benchmark in bin/ and the accuracy analysis in Implementation Comparison. To reproduce:
pnpm build
node bin/bench.mjs # or see bin/README.md for full setup
Bundle sizes are reproducible with:
pnpm build
du -sh dist/index.mjs dist/index.cjs
gzip -c dist/index.mjs | wc -c # gzipped ESM
gzip -c dist/index.cjs | wc -c # gzipped CJS
See Also
- Implementation Comparison - accuracy table and full API convention analysis
- Architecture - module structure and algorithm overview