Author: Les Fernandez
Date: 11:57:26 08/24/04
Go up one level in this thread
On August 24, 2004 at 13:33:51, Robert Hyatt wrote: >On August 24, 2004 at 13:11:24, Torstein Hall wrote: > >>On August 24, 2004 at 11:52:53, Robert Hyatt wrote: >> >>>On August 24, 2004 at 11:00:18, Vincent Diepeveen wrote: >>> >>>>On August 24, 2004 at 10:42:51, Robert Hyatt wrote: >>>> >>>>>On August 24, 2004 at 09:06:05, Jorge Pichard wrote: >>>>> >>>>>>On August 24, 2004 at 06:16:26, Vincent Lejeune wrote: >>>>>> >>>>>>> >>>>>>>A SYSTEM INTEGRATOR has started selling 5U eight way Opteron systems. >>>>>>> >>>>>>>http://www.theinquirer.net/?article=18035 >>>>>>> >>>>>>>I think it's the first 8-way system since the beginning of opteron. >>>>>>> >>>>>>>Great news for computer chess where a lot of 4 way was used in tournaments since >>>>>>>1 year ! >>>>>> >>>>>> >>>>>>It would had been a tough fight if shredder was using one against Hydra :-) >>>>>> >>>>>>Jorge >>>>> >>>>> >>>>>1. It takes even more tuning as it is still a NUMA box. On the 4-way and 2-way >>>>>boxes memory is local, 1 hop or 2 hops away. This adds to that. >>>>> >>>>>2. it won't be 2x faster as nobody scales perfectly. IE Crafty would probably >>>> >>>>Scaling = the increase in nodes a second. >>>>Speedup (efficiency) = the speedup in time you get out of the box >>> >>>No. Those are _your_ definitions. >>> >>>traditional scaling means simply "as you increase the number of processors, how >>>much does that reduce the total runtime." There are very _few_ applications >>>that exhibit this NPS vs search time anomoly. Nobody cares in the world of >>>parallel programming. >>> >>>I care because if I can't run 4x the NPS on 4 processors, I am losing something >>>that I don't necessarily have to lose. Hence the stuff done before the WCCC to >>>solve this on the opterons which started off producing pretty bad NPS increases. >>> >>>But the rest of the world only cares about total runtime... >>> >>> >>>> >>>>DIEP scales 100% on such 8 processor boxes. >>> >>>So do I. >>> >>>> >>>>>be about 1.7X faster, more or less depending on lots of things. That is not >>>>>enough to make up for the apparent difference in playing strength between >>>>>Shredder and Hydra. IE Hydra appears to be 200+ points stronger based on a >>>>>final result of 6-2. 1.7X faster won't get 200 points for Shredder... >>>> >>>>To my information Hydra runs currently on a 2 processor FPGA system. New fpga >>>>processors, as chrilly is busy rewriting his parallel search. >>> >>>Web site contradicts that but since I don't have access to real data, I have no >>>idea what they are running on. But based on the results against shredded, I >>>really have trouble beliveing they are using just two processors. They >>>apparently are at least 200 Elo stronger based on the match. >> >>Is it not a bit early to draw such a conlcusion after a 8 games match. I guess >>you have seen a lot longer series where the outscored program turns it around >>and scores better later on. And statistically I do not think it can be sayd 200 >>points with hig probability. >> >>Torstein > >While I agree somewhat, there are some circumstances that led to my conclusion: > >(1) long time control so no "blitz mistakes" creep in. > >(2) primary authors are running both so there is little chance of a poor >configuration set-up to skew the results. > >(3) the games themselves make it look almost easy at times. And when a program >wins "easily" it is news. > >My impression is that Hydra is simply out-searching Shredder badly. I don't >have quite the same feeling about Hydra's evaluation as I have seen a few >strange moves that other programs don't even consider. But then I saw the >_same_ thing back in the Deep Thought days, and just maybe those "strange moves" >are really best with a very deep/fast search. Hi Bob, Any idea as to how deep Hydra is searching or NPS ?? Just curious. Les > > >> >> >>> >>>> >>>>He has to as they were talking already times ago about a 512 processor hydra >>>>version (they = university paderborn which doesn't do the actual implementation >>>>of the parallel algorithm, chrilly does do that). >>>> >>>>The current implementation of hydra doesn't store last 3 ply in software, not to >>>>mention the last 3 ply in hardware, anything in hashtables. >>>> >>>>The entire hashtable from each node gets broadcasted to all other nodes and >>>>stored there. >>>> >>>>That's a O(N^2) operation trivially and doesn't scale. >>>> >>>>The actual speedup of hydra is not objectively measured so far. Just claiming 12 >>>>out of 16 without showing any actual data and already knowing that the single >>>>cpu test doesn't use last 3 ply a hashtable, where any software program does do >>>>that single cpu, is not a very nice comparision trivially. >>> >>>I haven't seen _any_ parallel search data other than my own, so all I can >>>comment on is what I get... >>> >>> >>>> >>>>The 8 processor opteron cannot be compared with the cluster at which Hydra soon >>>>again will run when the parallellism has been succesfully rewritten to something >>>>that actually works better. >>>> >>>>The latency to do a single pingpong operation is 16 microseconds at the hardware >>>>which is located in paderborn. Note that each node has 2 processors there and >>>>the new hardware getting build in UAE is 2 machines of 8 processors connected to >>>>each other. >>>> >>>>>These machines are not bad. There are _several_ companies with 8-way boxes >>>> >>>>There is not a single company selling 8 processor opteron boxes. It is well >>>>known there are some beta versions of those boxes which several companies use to >>>>test upon already for some years. >>> >>>Since I haven't tried to buy one, I won't comment. I _have_ run on one from two >>>different vendors within the past 12 months. And Sun was advertising one a >>>while back, whether they were shipping or not I can't say. >>> >>>> >>>>>ready to go. I ran on one at least 6 months ago. AMD has had one in their >>>>>development lab since well before the last CCT event...
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