Just a reminder that epsilon trick (invented by Jakub Pawlewicz) can be used to avoid excessive memory usage (reuse memory) without significant performance loss. It has been tested for proof number search, but there is no reason for it to behave differently in MCTS.
Lukasz Lew On Tue, May 12, 2009 at 19:35, Michael Williams <michaelwilliam...@gmail.com> wrote: > Those numbers are the average after the tree has grown to 1B nodes. I'm > sure the cache hates me. Each tree traversal will likely make several reads > from random locations in a 50 GB file. > > > Don Dailey wrote: >> >> So you are saying that use disk memory for this? >> This could be pretty deceiving if most of your reads and writes are >> cached. What happens when your tree gets much bigger than available >> memory? >> >> - Don >> >> >> >> On Tue, May 12, 2009 at 1:18 PM, Michael Williams >> <michaelwilliam...@gmail.com <mailto:michaelwilliam...@gmail.com>> wrote: >> >> In my system, I can retrieve the children of any node at a rate of >> about 100k nodes/sec. >> >> And I can save nodes at a rate of over 1M nodes/sec (this is much >> faster because in my implementation, the operation is sequential on >> disk). >> >> Those numbers are from 6x6 testing. >> >> >> Don Dailey wrote: >> >> This is probably a good solution. I don't believe the memory >> has to be very fast at all because even with light playouts you >> are doing a LOT of computation between memory accesses. >> All of this must be tested of course. In fact I was >> considering if disk memory could not be utilized as a kind of >> cache. The secret would be to store complete trees in disk >> memory, trees that are not likely to be utilized but can be >> utilized in a pinch. The tree store and retrieved must >> outweigh by a large factor the amount of time spent creating the >> tree in the first place in order for this to pay off. >> My guess is that this is impractical, but it's fun to think >> about how it might be done. I'm not sure how to do it without >> having a caching nightmare. >> >> >> - Don >> >> >> >> On Tue, May 12, 2009 at 12:41 PM, Michael Williams >> <michaelwilliam...@gmail.com >> <mailto:michaelwilliam...@gmail.com> >> <mailto:michaelwilliam...@gmail.com >> <mailto:michaelwilliam...@gmail.com>>> wrote: >> >> Don Dailey wrote: >> >> On Tue, May 12, 2009 at 12:16 PM, Michael Williams >> <michaelwilliam...@gmail.com >> <mailto:michaelwilliam...@gmail.com> >> <mailto:michaelwilliam...@gmail.com >> <mailto:michaelwilliam...@gmail.com>> >> <mailto:michaelwilliam...@gmail.com >> <mailto:michaelwilliam...@gmail.com> >> >> <mailto:michaelwilliam...@gmail.com >> <mailto:michaelwilliam...@gmail.com>>>> wrote: >> >> I have a trick ;) >> >> I am currently creating MCTS trees of over a billion >> nodes on >> my 4GB >> machine. >> >> >> Ok, I'll bite. What is your solution? >> >> >> I use an SSD. There are many details, of course. But it's >> still in >> the works and I'm still making lots of changes and >> adjustments. I >> seem to be able to "solve" (there are lots of definitions) >> 6x6 Go in >> that when I use a komi of 3.5, it is unable to find a winning >> line >> for white and when I use 4.5, it is unable to find a winning >> line >> for black. >> >> >> _______________________________________________ >> computer-go mailing list >> computer-go@computer-go.org >> <mailto:computer-go@computer-go.org> >> <mailto:computer-go@computer-go.org >> <mailto:computer-go@computer-go.org>> >> >> http://www.computer-go.org/mailman/listinfo/computer-go/ >> >> >> >> >> ------------------------------------------------------------------------ >> >> >> _______________________________________________ >> computer-go mailing list >> computer...@computer-go.org <mailto:computer-go@computer-go.org> >> http://www.computer-go.org/mailman/listinfo/computer-go/ >> >> >> _______________________________________________ >> computer-go mailing list >> computer...@computer-go.org <mailto:computer-go@computer-go.org> >> http://www.computer-go.org/mailman/listinfo/computer-go/ >> >> >> >> ------------------------------------------------------------------------ >> >> _______________________________________________ >> computer-go mailing list >> computer-go@computer-go.org >> http://www.computer-go.org/mailman/listinfo/computer-go/ > > _______________________________________________ > computer-go mailing list > computer-go@computer-go.org > http://www.computer-go.org/mailman/listinfo/computer-go/ > _______________________________________________ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
