It is quite memory hungry since near the leaves there are many positions with very few active children. On 9x9 I let a few playouts go through a move before expanding it, and that gives me plenty of memory. I ship with a default of 300 MB reserved for the hash table, and that's enough.
David > -----Original Message----- > From: [email protected] [mailto:[email protected]] > On Behalf Of Mark Boon > Sent: Monday, May 10, 2010 11:58 PM > To: [email protected] > Subject: Re: [Computer-go] effectiveness of transposition tables for go > > > On May 10, 2010, at 8:04 PM, David Fotland wrote: > > > Many Faces just has a hash table, no tree. There are no pointers to parents > > or children in the hash table. There is a linked list for collisions. > > Nodes are bigger, because each node contains an array of all legal moves and > > their RAVE values. However, I think this is more cache friendly than > > walking a linked list of children. > > Thanks, that's a clear explanation. So basically the move and the RAVE values > act as the reference to the next position. But I can see how it's more > efficient with respect to a cache as you don't have to follow pointers to get > the win-rate for each move from a potentially remote location. That makes some > sense to me. Do you do something special at the leaves? As otherwise I can see > this gets memory hungry very quickly. > > > When MFGO had really light playouts it was doing about 53K 9x9 playouts a > > second per 2.4 GHz core. Now it's more like 7K 9x9 playouts a second per > > core. > > I take it the light playouts didn't do much more than calculating liberties? > From 53K down to 7K means you do considerable extra work. Is that due to the > original MFGO engine? Because in Java I could still do a lot of pattern > matching and tactical reading before it would be down to 6K-7K per second on > one core. > > Mark > > _______________________________________________ > Computer-go mailing list > [email protected] > http://dvandva.org/cgi-bin/mailman/listinfo/computer-go _______________________________________________ Computer-go mailing list [email protected] http://dvandva.org/cgi-bin/mailman/listinfo/computer-go
