# OpenStream benchmark — nixamp 0.24.2

Generated 2026-09-13T09:48:49.844Z · envelope NXS1 · schema 1

**Environment.** node v24.20.0, zstd 1.5.7, zlib 1.3.2.1-motley-42c2f19, on linux 6.17.0-1022-azure x64, 4× INTEL(R) XEON(R) PLATINUM 8573C, 15.6 GiB.

**Policy.** block 262144 B; eligible at 3% and 512 B; zstd levels 1, 3, 9.

## Corpus

| sample | kind | bytes | container | best mode | saves |
| --- | --- | ---: | --- | --- | ---: |
| random-1mib | synthetic | 1048576 | bytes | stored | stored |
| zeros-1mib | synthetic | 1048576 | bytes | zstd L9 | 99.97% |
| text-repeat-1mib | synthetic | 1048576 | bytes | zstd L1 | 99.95% |
| ts-padded-50pct | synthetic | 752000 | mpegts | ts-zstd L1 | 50.04% |
| ts-unpadded | synthetic | 752000 | mpegts | stored | stored |
| tiny-3b | synthetic | 3 | bytes | stored | stored |
| empty | synthetic | 0 | bytes | stored | stored |

## Aggregate, per mode across the corpus

| mode | wire bytes | saving | enc ms | dec ms | round trip |
| --- | ---: | ---: | ---: | ---: | --- |
| stored | 4651091 | -0.03% | 0 | 0 | ok |
| gzip L6 | 2185882 | +52.99% | 57.09 | 10.94 | ok |
| zstd L1 | 2180173 | +53.11% | 14.55 | 9.62 | ok |
| zstd L3 | 2178281 | +53.15% | 12.8 | 8.59 | ok |
| zstd L9 | 2178204 | +53.15% | 53.79 | 8.85 | ok |
| ts-zstd L1 | 1127952 | +25% | 9.27 | 4.87 | ok |

## Caveats

- Envelope v1: a 16-byte stream header, a 48-byte header per frame, plus one end frame.
- OpenStream is a framing envelope over Zstandard and gzip, not a new compression algorithm; these numbers are those codecs at the block boundary, honestly framed.
- Synthetic samples do not predict production savings. A padded transport stream flatters a codec by its padding; an efficient real feed saves far less. Use --corpus with authorized real samples for numbers that mean something.
- Timings are wall-clock on the machine and runtime named in `environment` and do not transfer to other hardware.
- roundTrip:false in any row is a failure of exactness and must block a release.