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Re: About Amdahl's law 1 ...

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But Amine, you have said that the Amdahl's law predict scalability
of the worst case contention scenario , so the Amdahl's calculation in 
parallel computing looks like the calculation of  the worst case 
complexity in computer science?

That's right, cause what is, in your opinion , the purpose of the 
Amdahl's law if it's not to predict worst case scalability by 
calculating the maximum bound of time time inside the critical sections 
and the maximum bound of the time inside the parallel part and doing the 
Amdahl's calculation to predict the worst case contention scenario
hence the worst case scalability, so i think this will predict that the 
scalability will be equal or greater to the result that we have
found with the Amdahl's law. This is the purpose of Amdahl's law:
it's also to predict the worst case scalability.



Thank you,
Amine Moulay Ramdane.



On 10/10/2013 1:08 PM, aminer wrote:
>
> Hello,
>
> But how can we use the Amdahl's law to predict scalability ?
>
> You can not use the Amdahl's to predict the exact scalability,
> i think , and i have explained it to you that the Amdahl's laws
> in parallel computing gives you the scalability in the worst case
> contention scenario , so the Amdahl's calculation in parallel computing
> looks like the calculation of  the worst case complexity in computer
> science, so it can help to give the scalability
> of the worst case contention scenario, so that help also
> to predict worst case scalability, and if the serial part have not
> a constant running time and the parallel part have not a constant
> runnning time you can try to find and choose a maximum bound of
> the time to run the serial part and a maximum bound of the time to run
> the parallel part
> and do the Amdahl's calculation and this will give you the scalability
> for the worst case contention scenario, so the scalability will be equal
> or greater than the scalability that you will find with the Amdahl's
> equation.
>
>
>
> Thank you,
> Amine Moulay Ramdne.
>
>
>

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Thread

About Amdahl's law 1 ... aminer <aminer@toto.net> - 2013-10-10 13:08 -0700
  Re: About Amdahl's law 1 ... aminer <aminer@toto.net> - 2013-10-10 13:57 -0700
  Re: About Amdahl's law 1 ... Ben Bacarisse <ben.usenet@bsb.me.uk> - 2013-10-10 19:14 +0100
    Re: About Amdahl's law 1 ... aminer <aminer@toto.net> - 2013-10-10 14:45 -0700
      Re: About Amdahl's law 1 ... Ben Bacarisse <ben.usenet@bsb.me.uk> - 2013-10-10 20:56 +0100
  Re: About Amdahl's law 1 ... aminer <aminer@toto.net> - 2013-10-10 14:30 -0700
    Re: About Amdahl's law 1 ... Robert Wessel <robertwessel2@yahoo.com> - 2013-10-10 23:12 -0500

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