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Subject: Re: The need to unmake move

Author: Sune Fischer

Date: 09:34:53 09/03/03

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On September 03, 2003 at 12:23:08, Vincent Diepeveen wrote:
>
>The only one who you are confusing is yourself.

Correct, I'm confused why _you_ think threads doing independent searches needs
to communicate all the time.


>DIEP runs fine at any latency, but the speedup simply gets a lot less when the
>latency goes up.
>
>There are many practical problems.
>
>You speak about shipping messages.
>
>When are you going to receive them. Check each millisecond?
>
>Or let the OS decide?

I think I explained this already in other parts of the thread.
You can check as often as you want, it's sending the message that's expensive,
not checking for it.

>The OS fires at 100Hz, so things like processes that are sleeping because of the
>OS putting them to sleep (when locking and for 600 times they can't get the
>lock) then you have a latency of 10 ms before the process is awake.
>
>You are aware of such problems?

Yes, but this is concerning spawning and killing searches, not communication
between active search threads, don't confuse the issues.

>DIEP only can run well parallel at a shitload of cpu's thanks to statistical
>chances that a scenario X doesn't happen much.
>
>That took 1.2 years fulltime work. Still tuning some details.
>
>There is a lot of communication. It is very easy to test this yourself.

So give me an example, don't blow smoke.

>Just get a cheap network card. Say 100mbit and connect 2 pc's. Now let them do a
>parallel search.
>
>Please report back to me when you have a speedup > 1.0, because initially you'll
>be slower than 1.0 i bet.

I bet not ;)

-S.



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