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v1.5.0-pre.1

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@github-actions github-actions released this 10 Aug 10:16
v1.5.0-pre.1
d506337

Important

This is a development pre-release published for testing and feedback. It is not the next stable Coco release, and search defaults or packaged builds may change before that release.

What's included

  • Reworked board-state, hashing, move-generation, NNUE accumulator, transposition-table, and search correctness foundations.
  • Expanded UCI support including MultiPV, Ponder, complete search limits, WDL reporting, and tablebase telemetry.
  • Optional BMI2/PEXT sliding attacks with a tested magic-bitboard fallback.
  • Deterministic datagen, reproducible artifact manifests, checksums, and broader correctness/portability testing.
  • Platform-specific Windows, Linux, Linux ARM64, Intel macOS, and Apple Silicon builds.

The current NNUE is embedded in every engine binary. This pre-release does not use a built-in opening book.

Which binary should I download?

File Platform Best For
coco-chess-windows-x86-64-bmi2.exe Windows Intel Haswell+ / AMD Zen 3+ (recommended for most x86 users)
coco-chess-windows-x86-64-avx2.exe Windows AMD Zen 1/2 / older Intel (if bmi2 version is slow)
coco-chess-windows-x86-64-avx512.exe Windows AVX-512-capable Intel/AMD CPUs
coco-chess-windows-x86-64-popcnt.exe Windows Older x86-64 CPUs with SSE4.1 + POPCNT
coco-chess-linux-x86-64-bmi2 Linux Intel Haswell+ / AMD Zen 3+
coco-chess-linux-x86-64-avx2 Linux AMD Zen 1/2 / older Intel
coco-chess-linux-x86-64-avx512 Linux AVX-512-capable Intel/AMD CPUs
coco-chess-linux-x86-64-popcnt Linux Older x86-64 CPUs with SSE4.1 + POPCNT
coco-chess-linux-arm64 Linux ARMv8 systems, including Raspberry Pi 5 and ARM servers
coco-chess-linux-arm64-dotprod Linux ARMv8.2 systems with dot-product support
coco-chess-macos-apple-silicon macOS Apple M1, M2, M3, M4
coco-chess-macos-x86-64-avx2 macOS Intel-based Mac
coco-chess-macos-x86-64-popcnt macOS Older Intel Mac without AVX2

Note: The NNUE weights are embedded directly in each binary — no separate .nnue file is needed.

Pure calculation: Coco has no built-in opening book and no release artifact contains one. GUI-provided books are external to the engine.

BMI2 note: On AMD Zen 1 and Zen 2 CPUs, BMI2/PEXT is emulated in microcode (slow). Use the avx2 binary instead.

AVX-512 note: Use the AVX-512 binary only when your CPU explicitly supports AVX-512F, BW, DQ, and VL. Otherwise use BMI2, AVX2, or POPCNT.

Setup

  1. Download the binary for your OS and CPU.
  2. Place it wherever you store engine executables.
  3. Add it to your GUI (Arena, BanksiaGUI, Cute Chess, etc.) and set the binary path.

Please report crashes, illegal moves, time losses, malformed PVs, or unexpected platform problems through GitHub Issues.

See CHANGELOG.md for the complete provisional change list.

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