Author: Tom Kerrigan
Date: 21:11:11 06/29/00
Go up one level in this thread
On June 29, 2000 at 23:31:32, Robert Hyatt wrote:
>On June 29, 2000 at 23:02:08, Tom Kerrigan wrote:
>
>>On June 29, 2000 at 21:42:59, Albert Silver wrote:
>>
>>>On June 29, 2000 at 13:25:19, Tom Kerrigan wrote:
>>>
>>>>On June 29, 2000 at 03:38:38, Albert Silver wrote:
>>>>
>>>>>On June 29, 2000 at 02:21:10, Gregor Overney wrote:
>>>>>
>>>>>>>Not even close yet. That hardware would be approximately 1% of the power of
>>>>>>>the DB hardware. And that is being _very_ generous...
>>>>>>
>>>>>>1% is a pretty good estimate for a four processor machine using four P5-4
>>>>>>running at 1.5 GHz using a four channel RDRAM bus that delivers 3.2 GB of data.
>>>>>>Estimate 500 kNodes per CPU times 4 = 2M Nodes = 1% of DB's avarage performance.
>>>>>
>>>>>If one CPU achieves 500k nodes, I doubt very much that 4 CPUs will achieve 2M
>>>>>nodes, unless 100% efficiency has been achieved. Crafty is apparently the most
>>>>>efficient at this level though only Bob would be able to say how well it should
>>>>>do.
>>>>
>>>>No, believe it or not, Bob Hyatt is not the only competent chess programmer in
>>>>the world.
>>>
>>>:-))) Clearly you are trying to trick me Oh Evil One! But I am not fooled by
>>>your daring attempts to lure me into your dastardly plots!
>>>
>>>Seriously though, all I said was that as far as I knew ("apparently") Crafty was
>>>the most efficient multi-processor chess program among the micros. This wasn't
>>>based on any worshipping of the 'Great One', but on what I had been led to
>>>understand from my reading here. If there is a microcomputer chess program that
>>>makes better use of multi-processor systems, please just say which.
>>
>>AFAIK, Crafty uses a fairly common/simple MP algorithm. It's possible that other
>>micro programs are not using a better algorithm, but I doubt they're doing any
>>worse.
>>
>>>>In any case, who says that DB was searching at 100% "efficiency"?
>>>
>>>Actually, I wasn't talking about DB's efficiency at all, but merely the
>>>well-known figure of 200M NPS. Greg had said that a four processor machine would
>>>reach 1% of DB average performance, and said this by merely multiplying the NPS
>>>achieved by each processor. I questioned this conclusion and waited to be
>>>corrected, that's all.
>>
>>If you're just talking about NPS overhead, it's not that significant. Adding up
>>the NPS is pretty valid.
>>
>>-Tom
>
>
>Why the need to 'speculate' on what I am doing? I am not doing a "common/
>simple" MP algorithm. Not by a long shot. You only have to study the source
>to see, of course, rather than guessing.
I have enough source code to study, I don't need to look at yours too.
I believe you made posts to CCC saying that Crafty uses a simple implementation
of YBW, which I assume is similar to what Rainer Feldmann calls YBW. In which
case, it doesn't seem extremely special to me.
But if my memory is faulty or you have improved your algorithm, then sure, I
guess you're the best. Whatever.
-Tom
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