Ursus 1.1.0 🐻
Lots of search improvements and time management improvements since the last release.
Elo comparison from the last 1.0.1 release
DFRC_4852_v1.epd
STC: Elo | 71.06 +- 8.05
LTC: 72.25 +- 12.79
8moves_v3.epd
STC: 60.36 +- 6.39
Downloads
Which binary do I download?
If you're not sure, pick the avx2 build for your OS
| Platform | Recommended | If it won't run (older CPU) |
|---|---|---|
| Linux x86_64 | ursus-linux-x86_64-avx2 |
ursus-linux-x86_64-v2, then ursus-linux-x86_64-sse2 |
| Windows x86_64 | ursus-windows-x86_64-avx2.exe |
ursus-windows-x86_64-v2.exe, then ursus-windows-x86_64-sse2.exe |
| macOS (Intel) | ursus-macos-x86_64-avx2 |
— |
| macOS (Apple Silicon) | ursus-macos-aarch64-m1 |
— |
| Linux ARM64 | ursus-linux-aarch64 |
— |
| Android (ARM64) | ursus-android-aarch64 |
— |
Tuned builds (optional, for extra speed)
These are the same engine compiled for specific hardware. They can be a little faster than the generic build above but will crash or refuse to run on the wrong CPU — only grab one if it matches your chip.
| Your hardware | Binary |
|---|---|
| AMD Ryzen 1000 series (Zen 1) | ursus-linux-x86_64-znver1 / ursus-windows-x86_64-znver1.exe |
| AMD Ryzen 5000 series (Zen 3) | ursus-linux-x86_64-znver3 / ursus-windows-x86_64-znver3.exe |
| AMD Ryzen 9000 series (Zen 5) | ursus-linux-x86_64-znver5 / ursus-windows-x86_64-znver5.exe |
| AVX-512 CPU (Zen 4/5, Intel server) | ursus-linux-x86_64-avx512 / ursus-windows-x86_64-avx512.exe |
| Apple M4 | ursus-macos-aarch64-m4 |
| ARM Neoverse N1 server | ursus-linux-aarch64-neoverse |
| ARMv8.2 phone (Cortex-A76+) | ursus-android-aarch64-v8.2 |
On macOS, unsigned binaries trigger Gatekeeper. Either right-click → Open the first time, or run xattr -d com.apple.quarantine ursus-macos-* after downloading.
On Linux/macOS, you may need to chmod +x the binary before running it.
Verifying your binary
Run ./ursus bench from a terminal. You should see 5985347 nodes on the last line — if you see a different number, please open an issue with your platform details so we can track down any issues.