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Subject: Re: Anything to this hyperbola bitboard URL?

Author: Larry Griffiths

Date: 10:28:46 09/27/00

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On September 27, 2000 at 12:29:01, Vincent Diepeveen wrote:

>On September 26, 2000 at 13:51:17, Larry Griffiths wrote:
>
>>I was looking at these URL's.
>>
>>http://members.tripod.com/~RyanMack/computer.htm
>>http://members.tripod.com/~RyanMack/hypertech.htm
>>Does this look promising for bitboards?
>
>>Larry.
>
>The guy who wrote this nonsense is completely sick and
>knows very little from software and even less from hardware.
>
>First of all he doesn't seem to know the difference
>between assembly and between c++, secondly he's confusing
>generation speed of a program with search speed.
>
>Note that DIEP GENERATES about 15.5M nodes a second on a 450Mhz PII
>processor, but that its search speed is a 1000 times less.
>
>Searching at a couple of million nodes a second in an efficient way
>is simply impossible when using alfabeta+nullmove with a quiescencesearch.

Tell me about it.  my 1.5 million nodes a second drops to 300-500 thousand
nodes per second with ab+qs.

>
>just minimaxing is of course no problem, but you'll end up searching
>6 ply or so then.
>
>like 100 clocks a node in assembly at the intel processor is impossible,
>especially with bitboards.
>
>Also he quotes Bob wrong. You don't suffer 15-20 penalties from a memory
>reference, the latency of fast 133Mhz SDRAM is already more than that.
>
>The fastest 133Mhz SDRAM-222 needs 7.5ns x 10 = 75 clocks latency.
>
>The fastest PC800 memory needs 1.25ns x 15 = about 19 clocks latency
>
>Now we didn't talk yet about the 266PII with the real slow 66Mhz SDRAM
>which this guy has...
>
>If 'his' hyperbola suffers penalties because of misprediction, and you sure
>will suffer a lot of those when searching, then you suffer for each
>misprediction at least 10 clocks. A few branches and you're already
>slower as what he quotes.
>
>This guy is completely crazy and nuts and he sure knows nothing from
>programming. Sounds more like a lunatic who has written some stupid nonsense
>and i sure don't know why and what for, but it looks more like a vendetta
>against Bob for no reason.

Thanks for the post, Vincent.

I was thinking that about half of it is nonsense...

Larry.




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