Author: Vincent Diepeveen
Date: 08:00:18 08/24/04
Go up one level in this thread
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 DIEP scales 100% on such 8 processor boxes. >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. 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. 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. >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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