On Mon, May 10, 2010 at 02:26:18PM -1000, Mark Boon wrote: > >Don't you remember that Mogo had an issue with memory? > > Yes, I remember. Like I said, I've seen people write about memory > issues. But I just never understood where they came from. I'd like to > understand, as I don't see how they could follow from keeping the > nodes.
It seems memory issues start to pop up when you try to support very long thinking times (minutes per move) or massive influx of simulations (cluster computation). Pachi was originally extremely wasteful about memory (malloc()ating each single node separately!) and it never really mattered (unless you wanted to play very slow on 19x19) until Jean-loup had to fix that in order to handle many-core machines sensibly - tens of cores simulating in parallel will grow the tree very quickly. ;-) > On Mon, May 10, 2010 at 1:37 PM, Don Dailey <[email protected]> wrote: > If it was 2 or 3 min. for 19x19 it's a little easier to understand. > It's still a lot longer than you can think on average. Pachi is used to playing with 25/5:00 timesetting on KGS and commonly runs out of its reserved 3GiB of memory on the final moves in the period when it can easily spend 30s on a single move _and_ gets simulations from 8 i7 cores. Usually when it is going through a narrow sequence where major portion of the tree get reused in the following moves > Plus, for 19x19 > you cannot do playouts nearly as fast as on 9x9. The 5 times longer > game-length gets compounded by the need for heavier playouts. >From my experience, the tree still grows noticeably quicker on 19x19, the much larger node expansion rate seems to quite outweight our heavy playouts cost just yet. -- Petr "Pasky" Baudis When I feel like exercising, I just lie down until the feeling goes away. -- xed_over _______________________________________________ Computer-go mailing list [email protected] http://dvandva.org/cgi-bin/mailman/listinfo/computer-go
