Michael Williams: <[email protected]>: >Well, not literally useless, as long as you are building a tree equally >fast.
Well, but the tree is expanded in a wrong direction, which is also useless, isn't it? #I'd like to agree to add "almost" is literally correct but I believe that speed is really useless in that case. It's unknown if expanding tree in wrong directions helps. According to the convergence theorem of UCT, I bet this does not help becaues the simulations return wrong results. Hideki >On Wed, Jun 1, 2011 at 8:13 PM, Hideki Kato <[email protected]> wrote: > >> Although speed matters, the quality of simulations is dominant. When >> the simulations cannot manage a postion correctly, speed is useless. >> >> Hideki >> >> Bojun Huang: <[email protected]>: >> >It seems to me that, there is a thread of efforts that try to improve the >> playing capability >> >of GO bots by dramatically increasing playouts/sec. Now we know that FPGA, >> GPU, and SIMD can >> >make much more playouts per second than single-core CPU, but all these >> results are based on >> >"light" playout schemes. So everytime when these kind of results come out, >> people would doubt >> >the likelihood that these designs really generate strong programs. >> > >> >So my question is, Is there a "widely accepted" baseline performance to >> compare with for all >> >these works? >> > >> >For example, we may pick a known program with "lightest" playout scheme >> among those >> >frequently attending the KGS monthly. So if a high-performance design >> implements similar >> >playout scheme of that program but achieves much higher playout/sec, we >> could reasonably >> >expect a stronger program based on this design. >> > >> >Another question ... does more playouts really provide a *consistent* >> improvement on the ELO >> >score, especially for those strongest programs? I remember that some >> programs running on >> >laptop rank very high in the Olympaids, that seems imply that speed simply >> doesn't matter >> >here ... >> > >> >Thanks, >> >Bojun Huang >> > >> >>Date: Wed, 25 May 2011 22:23:29 +0200 >> >>From: Antoine de Maricourt <[email protected]> >> >>To: [email protected] >> >>Subject: Re: [Computer-go] Direct DX11 and graphics cards for cheaper >> >> simulation hardware? >> >>Message-ID: [email protected]> >> >>Content-Type: text/plain; charset=ISO-8859-1; format=flowed >> >> >> >> >> >>> Despite the challenges using it in a tree, and the contentious issue of >> >>> whether light playouts can make a really strong program, I think this >> is >> >>> interesting research. By 1.6 times quicker than libego, do you mean as >> >>> it runs on the CPU? Or is this a simulated speed as if it was running >> on >> >>> the GPU? I think libego was the clear leader in light playout speed, so >> >>> working out a way to do playouts even faster (if that is what you have >> >>> done) is amazing. >> >>I just emulated data structures and algorithms that are targeting GPU >> >>in C++ for a CPU. 128-bit CPU's SIMD instruction set simply emulates 4 >> >>GPU-like threads working on 32-bit registers. After several attempts >> >>made to test various ideas, the first complete implementation had >> >>performances similar to libego, without a simple CPU specific >> >>optimization. I then put back some specific CPU optimizations (not >> >>likely to be effective on GPU) + tuning and easily improved the >> >>performances. This is really how it runs on the CPU. The same data >> >>structure and algorithm is likely to have an even better ratio against >> >>libego with an AVX enabled processor. >> >> >> >>Light playout was a beginning to start with. The random move generator >> >>has been designed to take into account a probability distribution (with >> >>a little slowdown) that can be derived from local pattern matching. >> >> >> >>Regards, >> >> >> >> Antoine >> >---- inline file >> >_______________________________________________ >> >Computer-go mailing list >> >[email protected] >> >http://dvandva.org/cgi-bin/mailman/listinfo/computer-go >> -- >> Hideki Kato <mailto:[email protected]> >> _______________________________________________ >> Computer-go mailing list >> [email protected] >> http://dvandva.org/cgi-bin/mailman/listinfo/computer-go >> >---- inline file >_______________________________________________ >Computer-go mailing list >[email protected] >http://dvandva.org/cgi-bin/mailman/listinfo/computer-go -- Hideki Kato <mailto:[email protected]> _______________________________________________ Computer-go mailing list [email protected] http://dvandva.org/cgi-bin/mailman/listinfo/computer-go
