Large-Scale Parallel Monte Carlo Tree Search on GPU

Kamil Rocki, Reiji Suda
<span title="">2011</span> <i title="IEEE"> <a target="_blank" rel="noopener" href="" style="color: black;">2011 IEEE International Symposium on Parallel and Distributed Processing Workshops and Phd Forum</a> </i> &nbsp;
Monte Carlo Tree Search (MCTS) is a method for making optimal decisions in artificial intelligence (AI) problems, typically move planning in combinatorial games. It combines the generality of random simulation with the precision of tree search. The motivation behind this work is caused by the emerging GPU-based systems and their high computational potential combined with relatively low power usage compared to CPUs. As a problem to be solved I chose to develop an AI GPU(Graphics Processing
more &raquo; ... based agent in the game of Reversi (Othello) which provides a sufficiently complex problem for tree searching with non-uniform structure and an average branching factor of over 8. I present an efficient parallel GPU MCTS implementation based on the introduced 'block-parallelism' scheme which combines GPU SIMD thread groups and performs independent searches without any need of intra-GPU or inter-GPU communication. I compare it with a simple leaf parallel scheme which implies certain performance limitations. The obtained results show that using my GPU MCTS implementation on the TSUBAME 2.0 system one GPU can be compared to 100-200 CPU threads depending on factors such as the search time and other MCTS parameters in terms of obtained results. I propose and analyze simultaneous CPU/GPU execution which improves the overall result.
<span class="external-identifiers"> <a target="_blank" rel="external noopener noreferrer" href="">doi:10.1109/ipdps.2011.370</a> <a target="_blank" rel="external noopener" href="">dblp:conf/ipps/RockiS11</a> <a target="_blank" rel="external noopener" href="">fatcat:zqnpuk47rrg4joasfoetnjfe24</a> </span>
<a target="_blank" rel="noopener" href="" title="fulltext PDF download" data-goatcounter-click="serp-fulltext" data-goatcounter-title="serp-fulltext"> <button class="ui simple right pointing dropdown compact black labeled icon button serp-button"> <i class="icon ia-icon"></i> Web Archive [PDF] <div class="menu fulltext-thumbnail"> <img src="" alt="fulltext thumbnail" loading="lazy"> </div> </button> </a> <a target="_blank" rel="external noopener noreferrer" href=""> <button class="ui left aligned compact blue labeled icon button serp-button"> <i class="external alternate icon"></i> </button> </a>