Space Channel 5 native preview 2 — performance update

This preview reduces CPU overhead behind the low-frame-rate/slow-audio reports.

On the development PC, repeated Report 3 replays measured 24.9–26.2% more processing throughput. A matched audio-paced replay went from 23,808 audio underrun frames to zero, while preserving CPU state, RAM and generated audio. These are scene-specific Windows measurements, not a performance guarantee for every machine.

• Optimized native clock setup and shared-state access.
• Profile-guided Windows builds, with no new AVX2 requirement or player compiler installation.
• Graphics, game-speed, frame-timing and audio diagnostics in userdata/last-launch.log.
• 64 Windows regression tests and 240 additional clock/branch checks passed; bounded replays of all four reports preserve gameplay output.

Extract the package for your system, run SpaceChannel5, and select your original USA GDI. Keep your existing userdata when updating.

Linux/macOS packages include the shared optimizations, without the Windows execution profile. Physical Steam Deck and reporter-hardware testing is still needed; issue #1 remains open. Uneven presentation intervals can still occur.

Measurements and validation · Player guide

Corresponding source, generated native-code source and SHA-256 checksums are included with the downloads. Original disc assets are supplied by the player.

Space Channel 5 native preview 0.1.0

Download the archive for your platform, extract it, run SpaceChannel5, select your own original USA Dreamcast GDI, and choose Play. Keep the GDI and its tracks available. No Python, Git or compiler installation is required.

This preview includes precompiled native game modules and an asset importer, with no original disc assets or saves bundled.

• Windows x64, Linux x64/ARM64, and macOS Intel/Apple Silicon packages.
• Original 4:3, widescreen fit, crop, stretch, and experimental expanded-geometry options. Original framing remains the default; prerecorded backgrounds remain 4:3.
• Optional 60 Hz geometry interpolation. Game logic, input and music clocks are unchanged; interpolation can add visual delay and does not interpolate prerecorded video.
• Keyboard/controller remapping, Steam Input support, volume/buffering, rhythm calibration and optional texture/native mods.

Windows validation includes 64 native regression passes, matched state/audio replays, a fresh compiler-free import/boot test, and isolated default/interpolated audio tests with zero underruns. Earlier validation covered all four reports through credits in assist mode. Linux/macOS packages are CI-built and module/runtime-tested previews; full gameplay, graphics/audio and controller acceptance on those machines remains unverified. macOS packages are ad-hoc signed, not notarized.

See player instructions, validation, and platform details.

The corresponding-source archive includes project sources, pinned upstream dependency sources, and generated C matching the native modules. native-aot-source.tar.gz is also available separately for developers. Original game assets must come from the player.

Unofficial project; not affiliated with Sega.

Build evidence: native modules on all four CI targets, final packaged runtime checks.