Author: Vincent Diepeveen
Date: 08:38:37 01/29/03
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On January 28, 2003 at 10:33:15, Robert Hyatt wrote: >On January 28, 2003 at 09:07:35, Vincent Diepeveen wrote: > >>On January 28, 2003 at 03:33:44, Mig Greengard wrote: >> >>>According to the tech I talked with, Amir and Shay were testing both machines >>>before the match to see which one they would use. To my knowledge it wasn't >>>decided until a day or two before the match. Obviously there isn't a big >>>difference in performance. >>> >>>Saludos, Mig >>>http://www.chessninja.com >> >>thanks. >> >>DIEP onto the 8 processor 1.6 would be running 16 processes and speed would >>be about expressed in K7: >> 8 x 1.6 Ghz / 1.4 = 9 Ghz > > >No it wouldn't. You haven't tried an 8-way intel box yet. It doesn't scale >nearly as well as the 2-way and 4-way intel boxes do. The chipset for >supporting 8 cpus is simply not very good... DIEP isn't demanding much bandwidth Bob in case you missed it, it works great on a cc-NUMA machine too. >The 8-way box using the same clock speed for the processors will only be about >1.5X faster than the 4-way box, and that doesn't count parallel search overhead >at all. That's not true. It's 8 times faster for good software. Of course there is algorithmic loss but there is no sequential loss unless the software sucks, to say it rude. Doesn't say that it is easy to make software that can handle the latencies. It sure isn't easy to make a chessprogram that is having a good speedup (without a too big sequential loss first like Zugzwang which was slowed down first like 100 times or so in order to then have a decent speedup at like 256 processors; 50% speedup even incredible much i would be *very* happy with around 15% already). But it is possible to make. DIEP is such a program that shows it can. DIEP runs like the sun on 8 cpu's (2 nodes quad SGI), even at the slowest partitions (slowest latency speeds are of course at the biggest partitions: 512 cpu partition). A 8 processor Xeon is hell for pc software like Fritz, Junior, Crafty, but it is very good for DIEP. Best regards, Vincent
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