Triumviratus 8.1 is out. It is the official release that follows 8.0 and the 8.1 pre-releases of the last weeks.
While 8.1 was being prepared, Triumviratus 8.0 kept doing well on the CCRL lists of 7 November: on 40/15 it shares first place on 4 CPUs with Stockfish 19 (3650) and is first among the single-CPU engines (3635), on Blitz it is second (3784), and on the 40/2 FRC list it is second (4104).
Strength (UHO 2024 openings, 1 thread, large pages enabled for both engines):
- against Triumviratus 8.0: +21.5 +- 6.7 Elo over 2,508 games at 15+0.15
- against Stockfish 19: +0.3 +- 3.3 Elo over 8,860 games at 60+0.6
What is new
- Network: Consilium Plebis, with input buckets chosen separately for each side by the opponent's non-pawn material (the project calls them "experts"; the idea comes from the mixture-of-experts models of language AI), and a small pawn-king subnetwork added to every layer stack. Alone it is worth about +10 Elo over the 8.0 network.
- Search: every block rewritten in the project's own code, a quiet history that learns as a listwise ranker, and several changes measured one by one.
- Speed: faster evaluation and move ordering, with contributions from Houze Guo (AVX2, AVX-VNNI and AVX-512) and A Tin Man (move generator). The universal executable now carries each build exactly as it was optimised alone, each with its own PGO profile, built with clang 23.
- Fixes: the universal executable runs again on CPUs without AVX (issue #10), an 8 MB thread stack on every platform (issue #9), 64-bit Zobrist keys, and the fixes from the code review by Bastiii.
Files: one Windows executable for every x86-64 CPU (from SSE4.1 to AVX-512, the best build is chosen at start-up), Linux builds for any distribution, and macOS builds for Apple Silicon and Intel.
Position Solver: the 8.1 analysis build for hard positions is also released. On Eduard Nemeth's "256 difficult positions 2023" at 10 s per position, Maurizio Platino measured 173 solved with the Position Solver of 28 October, against 154 for ShashChess 42 and 146 for Stockfish 19. It is made for solving and analysing positions, not for games.
Thanks to Maurizio Platino (MortalSin), the project's main tester and search-tuner, who also shares the cost of training the networks; to Houze Guo, A Tin Man and Bastiii for their code; to Mark Tang for his testing and reports during development; and to CCRL and the whole computer chess community.
Triumviratus is becoming a community project: anyone who would like to join the Discord server can contact me.
Francesco
Download Triumviratus 8.1
Download Triumviratus 8.1 Position Solver
, mainly based on SF dev. with patches made by Claude based on role models like e.g Crystal, sorry for having it in list not planning to make it public, just as some kind of non- competitive benchmark for the suite and hardware- TC, the rest of the name stands for a certain single setting, QSEEP3 is Quiet SEE Pruning=3, KD1 is King Danger=1) ShashChess42C was a prerelease- version of ShashChess 42 I tested way back then, it wasn't publicly available neither and is outdated since release of 42.
