Multiple instances of Lc0 on a single GPU card

[MMarco]

Does anydoby have an idea about how running multiples instances of Lc0 on a single GPU will affect the randomness of the results if i run engine tets?

As an example when i run 4 instances of Lc0 with LS15 say on my GTX card, I can notice the nps is altered downward. Sometimes very much (all instance are running at the same time), sometimes moderately ,(two or three instances are running at the same time), sometimes there is no impact (only one instancce running).

Apart from weakening the engine with now lower average nps count, extra variablity is introduced due to fluctuating NPS for Lc0 ,(assume for now these Lc0 plays 4 instances of Stockfish and that I have enough ressources for that).

However, i run 4 times more games per day and if my goal is to discriminate between 2 differents settings of Lc0, would that be an efficient way to use my hardware? Can the advantage of running 4 times more games be more important that the increase in variability introduced by sharing the ressources on the GPU card, in terms on variance reduction when I come to evaluate the ratings after my tournament?

I dont now what to think about that. Comments,?

[Ozymandias]

I didn't even know you could run more than two instances, on a single GPU.

[MMarco]

I didn't even know you could run more than two instances, on a single GPU.

Yes, they run without problems in my case. I ran 4 instances of Allie Stein (20 x 256 net) vs 4 single threaded Stockfish in Cutechess GUI with concurrency = 4. I have a GTX 1660 with 6G ram. The load is about 3,5G with the 4 Allies running concurrently. The average NPS count is lower however. And I think that there are NPS fluctuations, (I'm not sure how large) too depending on the number of Allie instances currently thinking (I test with ponder off).

The games I ran looked normal but of course Allie score was lessened due to the lower nps average. The draw rate was lower too, but ORDO should take that into account I believe.

[Ozymandias]

I have a GTX 1660 with 6G ram. The load is about 3,5G with the 4 Allies running concurrently.

I have to see if 4GB are enough, then.