Author: Vincent Lejeune
Date: 02:46:32 08/25/04
Go up one level in this thread
On August 24, 2004 at 14:57:26, Les Fernandez wrote: >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. If I remember well, 20 Mn/s , cards could do the double but the PCI bus is a bottleneck, so with a PCI-Express bus , we can expect 40 Mn/s with 16 FPGA cards. > >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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