Thank you Oliver, Olivier Teytaud: <aa5e3c330911242304tc6b9e1bk466b1f08cb65d...@mail.gmail.com>: >> >> The performance gap is perhaps due to the algorithms. Almost all >> cluster versions of current strong programs (MoGo, MFG, Fuego and Zen) >> use root parallel while shared memory computers allow us to use thread >> parallelism, which gives better performance. > > >I think you should not have troubles with your networks, at least with >the number of machines you are considering. > >Perhaps you should increase a little the time between two communications ? >With something like mpi_all_reduce for averaging the statistics over all the >tree at each communication, more than 3 or 4 communications per second >is useless. Averaging statistics in nodes with less than 5% of the total >number of simulations might be useless also.
In your (or Sylvain's?) recent paper, you wrote less than one second interval was useless. I've observed similar. I'm now evaluating the performance with 0.2, 0.4, 1 and 4 second intervals for 5 second per move setting on 19x19 board on 32 nodes of HA8000 cluster. Though I have not enough games yet, current best is 1 second interval which improves about 400 Elo in self-play. Then, why we have similar experiments with different implementations of root parallelism, based on different programs and on different clusters? I don't use MPI for the cluster version of Zen. Zen's playouts are slower than MoGo's. Etc... One second is a mysterious time :(. Hideki -- g...@nue.ci.i.u-tokyo.ac.jp (Kato) _______________________________________________ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
