Lc0 + 320x24.J13B.2-swa-136000 vs. Stockfish 250919 TC= 30m+30s

[mwyoung]

logically it should be more for a RTX2080 ti.

Yes, that would explain mwyoung recommending 4 Threads, as he has a 2080 Ti.
At the same time, going overboard with the number of Threads also seems to be a bad idea.
One should find the correct balance.
Is using an odd number of threads a bad idea ?

I do not recommend 4 threads. I recommend what ever runs best on your system. You must tune to your CPU and GPU. Remember I am running a AMD 2950x. My cores are slower then say a 9900K. So when tuning it ran slightly better with 3 or 4 threads vs 2.

[mwyoung]

How many threads do TCEC and the other one (chess.com ?) tournaments use with Lc0 ?

Good question. How many GPU's are being used? My understanding is that you want two CPU "worker threads" for each GPU that the system has.

[EDIT] It seems that AllieStein at TCEC is running on 2 GPUs and Threads is set at default (since it's not listed in the settings).

There are many types of GPUs. Are we to assume that 2 threads work just as well on 980, 1080, RTX 2060, RTX 2070, RTX 2080, and RTX 2080 ti. Even when these cards at the top of performance stack. Run many times faster then the GPU cards on the lower end of the stack. Hmmm

But if I use 2 slower cards then it is ok to use 4 threads.

We have a tendency to always want to carve some ideas into stone. Without actually testing if are assumptions are correct.

Testing is good, provided it's done in a statistically valid way. On the other hand, when an Lc0 developer includes the following along with the code at Github, I tend to pay attention:

Number of (CPU) threads to use.
Default is 2. There's currently no use of making it more than 3 as it's limited by mutex contention which is yet to be optimized.

Yes, this is what I observed in tuning. My biggest jump came going from 2 threads to 3 threads. And a very slight jump at 4 threads. Any more then 4 threads and performance tanked on my system.

[shrapnel]

I do not recommend 4 threads. I recommend what ever runs best on your system. You must tune to your CPU and GPU. Remember I am running a AMD 2950x. My cores are slower then say a 9900K. So when tuning it ran slightly better with 3 or 4 threads vs 2.

OK. Actually 2 Threads seems to be giving best results while playing on Infinity Chess.
Ordered a ASUS ROG OC 11 GB 2080 Ti today, will post in a few days how many Threads appear optimal for it on my 8 CPU i7 5960X.

[Nordlandia]

At the same time, going overboard with the number of Threads also seems to be a bad idea.

What about using 3 threads for RTX 2080 Ti. An Intermediate value between 2 and 4. Maybe a sweet spot.

Markyoung: how do you position yourself to try 3 threads instead of recent experiment with 2 threads?

[mwyoung]

At the same time, going overboard with the number of Threads also seems to be a bad idea.

What about using 3 threads for RTX 2080 Ti. An Intermediate value between 2 and 4. Maybe a sweet spot.

Markyoung: how do you position yourself to try 3 threads instead of recent experiment with 2 threads?

Yes it could be. I will retune tonight. Since I have some time.
And since I also did not have time to see with the bigger nets now available. If a retune would help.

[shrapnel]

The bigger Nets seem to be very strong. All the more reason to upgrade to the 2080Ti, so as to take full advantage of the bigger Nets.