What's new in 4.2.1
This release replaces the evaluation network entirely.
GaiaNet-T1
More detailed threat features, and a larger network than before.
Which file should I download?
| File | Requires | Recommended for |
|---|---|---|
gaiachess-nnue-znver5.exe |
AMD Zen 5 | Ryzen 9000 series |
gaiachess-nnue-znver4.exe |
AMD Zen 4 | Ryzen 7000 series |
gaiachess-nnue-znver3.exe |
AMD Zen 3 | Ryzen 5000 series |
gaiachess-nnue-avx512.exe |
AVX-512 (Intel Ice Lake+) | Intel 11th gen+ |
gaiachess-nnue-avx2.exe |
AVX2 (Intel Haswell+, AMD Zen+) | Generic fallback for any modern CPU (2014+) |
gaiachess-pesto.exe |
Any x86-64 CPU | Older machines without AVX2 support |
How to check: on Windows, open a command prompt and run wmic cpu get name. Then:
- AMD Ryzen 9000 (Zen 5) →
nnue-znver5 - AMD Ryzen 7000 (Zen 4) →
nnue-znver4 - AMD Ryzen 5000 (Zen 3) →
nnue-znver3 - Intel 11th gen+ →
nnue-avx512 - AMD Ryzen 1000–3000 (Zen–Zen 2) or Intel Haswell–10th gen →
nnue-avx2 - Older CPUs (pre-2014, no AVX2) →
pesto
If unsure, try nnue-avx2 first — it works on any CPU made after ~2014. If it
crashes on startup, fall back to pesto.
The NNUE versions are several hundred Elo stronger than PeSTO thanks to the
neural network evaluation, but require AVX2 for the SIMD inference.
Each executable is self-contained: the neural network and the 3+4-piece DTM
tablebases are embedded, so there is nothing else to download.
UCI Options
| Option | Type | Default | Description |
|---|---|---|---|
| Hash | spin | 16 | Transposition table size in MB (1–1048576) |
| Threads | spin | 1 | Number of search threads (1–256) |
| EvalFile | string | <internal> | Path to a .nnue network file |
| Ponder | check | true | Enable pondering |
| MultiPV | spin | 1 | Number of principal variations (1–256) |
| Move Overhead | spin | 100 | Time buffer in ms for GUI/network lag (0–5000) |
| SyzygyPath | string | <empty> | Path to Syzygy tablebase files |
| NalimovPath | string | <empty> | Path to Nalimov tablebase files |
| OnlineTB | check | false | Query online tablebases when local ones are unavailable |
License
Gaia is distributed free of charge. Gaia may not be distributed as part of any
software package, service or web site without prior written permission from the
authors.
© 2003–2026 Jean-François Romang