Chess engine: Lc0 0.27.0-rc2 (Windows and Android)

Starting with this release, we are distributing two packages for windows with Nvidia GPUs: the cuda package and the cudnn package. The cudnn package is what we used to distribute so far (but we called it cuda), and comes with the same versions of cuda and cudnn dlls we were using for the last few months. The new cuda package comes with cuda 11.1 dlls and requires at least version 456.38 of the windows Nvidia drivers, and should give better performance on RTX cards and in particular the new RTX 30XX cards.

Notes:

The cudnn package will work as-is in existing setups, but for the cuda package you may have to replace cudnn with cuda (or cuda-auto or cuda-fp16) as a backend (if specified) - this will certainly be necessary for multi-gpu setups.

Some testing indicates that cuda 11.1 may be slower for GTX 10XX cards, so owners of older cards may want to stay with the cudnn package. If your testing shows otherwise do let us know.

v0.27.0-rc2

Fix additional cases where 'invalid move' could be incorrectly reported.

Replace WDL softmax in cudnn backend with same implementation as cuda backend. This fixes some inaccuracy issues that were causing training data to be rejected at a fairly low frequency.

Ensure that training data Q/D pairs form valid WDL targets even if there

is accumulated drift in calculation.

Fix for the calculation of the 'best q is proven' bit in training data.

Multiple fixes for timelosses and infinite instamoving in smooth time manager. Smooth time manager now made default after these fixes.

Lc0 0.27.0-rc2 download