Number of default threads for Lc0 31.0 Cuda

[MMarco]

Hi,

I noticed by typing 'uci' that Lc0 31.0 Cuda has zero as the number of default search threads, instead of the two threads we had before. I couldn't find an explanation about this in the release notes.

Moreover, when I add the engine in Fritz 17 GUI, it defaults to eight threads. Strange.

Should I set it back to two? Or that doesn't matter now? In Windows task manager, the CPU load is hardly different going from two to eight threads (as I'm using a BT4 net running around 4000nps on my card).

Thank you,

[Krzysztof Grzelak]

Yes, 2 or 3 threads.

[shawn]

There is no reason to use anything different then 2 threads if you are using a single GPU to evaluate. In fact, on Lc0 discord some people have found more threads on certain systems causing NPS to actually decrease.

Quote from borg (Leela developer)

You may need more threads if you have multiple GPUs or none at all.
...
With two search threads, one it typically preparing the next batch while the other is waiting for the gpu to finish processing the current batch.