Search found 2068 matches

by Michel
Thu Jan 16, 2020 7:45 am
Forum: Computer Chess Club: General Topics
Topic: Women World Fischer Random Championship 2019 Next Month in USA
Replies: 73
Views: 2442

Re: Women World Fischer Random Championship 2019 Next Month in USA

That's not what you are claiming. You have repeatedly gotten wrong what I'm claiming. Now I'm going to claim that you're the only person in the world that considers a King on c1 castling with a rook on h1 a legal chess move. If anybody reading this agrees with you and replies to this message saying...
by Michel
Fri Jan 10, 2020 7:51 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: RMO - Randomized Move Order - yet another Lazy SMP derivate
Replies: 113
Views: 5679

Re: RMO - Randomized Move Order - yet another Lazy SMP derivate

The above Dr. Dobbs journal article references this paper: https://www.researchgate.net/publication/221583842_Superlinear_Speedup_in_Parallel_State-Space_Search When N processors perform depth-first search on disjoint parts of a state space tree to find a solution, the speedup can be superlinear (i...
by Michel
Tue Jan 07, 2020 11:23 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: RMO - Randomized Move Order - yet another Lazy SMP derivate
Replies: 113
Views: 5679

Re: RMO - Randomized Move Order - yet another Lazy SMP derivate

It is only the fixed depth tests that I prefer v4, but there is no reason not to stop the search if one thread reaches the depth limit. It turns out Stockfish can be made stronger by simply repeating a single-threaded search at a given depth a number of times. In fact, it seems a single-threaded se...
by Michel
Mon Jan 06, 2020 7:45 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: RMO - Randomized Move Order - yet another Lazy SMP derivate
Replies: 113
Views: 5679

Re: RMO - Randomized Move Order - yet another Lazy SMP derivate

Vondele did an interesting experiment : I implemented 5 versions (drafts: https://github.com/vondele/Stockfish/commits/threadDepth) v1: Master version: all threads search irrespective of Limits.depth, mainThread stops search when it reaches limits depth. v2: First thread to reach Limits.depth stops...
by Michel
Sun Jan 05, 2020 8:58 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: RMO - Randomized Move Order - yet another Lazy SMP derivate
Replies: 113
Views: 5679

Re: RMO - Randomized Move Order - yet another Lazy SMP derivate

// Iterative deepening loop until requested to stop or the target depth is reached while ( (rootDepth += ONE_PLY) < DEPTH_MAX && !Threads.stop && !(Limits.depth && mainThread && rootDepth / ONE_PLY > Limits.depth)) Perhaps this is the culprit? If I read it correctly then the depth limit is only res...
by Michel
Sun Jan 05, 2020 12:01 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: RMO - Randomized Move Order - yet another Lazy SMP derivate
Replies: 113
Views: 5679

Re: RMO - Randomized Move Order - yet another Lazy SMP derivate

I modified this logic to make it never exceed the fixed depth limit and ran 8 threads vs 1 thread again at fixed depth 10. The result was +42.5 elo after 5536 games. Thanks. Interesting! This points indeed to a bit of widening. But I would argue that the elo difference is quite small for 3 thread d...
by Michel
Sun Jan 05, 2020 11:52 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: RMO - Randomized Move Order - yet another Lazy SMP derivate
Replies: 113
Views: 5679

Re: RMO - Randomized Move Order - yet another Lazy SMP derivate

// Iterative deepening loop until requested to stop or the target depth is reached while ( (rootDepth += ONE_PLY) < DEPTH_MAX && !Threads.stop && !(Limits.depth && mainThread && rootDepth / ONE_PLY > Limits.depth)) Perhaps this is the culprit? If I read it correctly then the depth limit is only res...
by Michel
Sun Jan 05, 2020 10:34 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: RMO - Randomized Move Order - yet another Lazy SMP derivate
Replies: 113
Views: 5679

Re: RMO - Randomized Move Order - yet another Lazy SMP derivate

You ran fixed depth games. Stockfish with 8 threads on 1 core will take much more time than Stockfish with 8 cores to reach the given depth, but will have a rather similar search tree in the end. Hence, having similar results with 1 or 8 cores using fixed depth for 8 threads is expected, though som...
by Michel
Sun Jan 05, 2020 5:37 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: RMO - Randomized Move Order - yet another Lazy SMP derivate
Replies: 113
Views: 5679

Re: RMO - Randomized Move Order - yet another Lazy SMP derivate

It looks "ridiclous theory number 1" could be the winner :) I redid the test at fixed depth=8 but this time constraining all 8 threads to 1 cores using "taskset -c 0 ./cutechess-cli", and i can see only 100% cpu usage when the previous test was 800% cpu usage. So both the single thread and multi-th...
by Michel
Sun Jan 05, 2020 12:07 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: RMO - Randomized Move Order - yet another Lazy SMP derivate
Replies: 113
Views: 5679

Re: RMO - Randomized Move Order - yet another Lazy SMP derivate

The story for Scorpio is the same at depth=14 too Score of scorpio-sht-8-thread vs scorpio-sht-1-thread: 78 - 90 - 132 [0.480] 300 BUT for stockfish, I was shocked to find out some +170 elo at fixed depth=8. Then I decided to investigate further by doing fixed depth tests starting from depth=1 Dept...