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Question on speed

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  • george hayes
    I created a program that is testing for potential primes at 10^1,000,000,000+. My test yesterday was from 10^1,000,000,000 to 10^1,000,000,000+1,000,000 it
    Message 1 of 4 , Jan 13, 2007
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      I created a program that is testing for potential primes at 10^1,000,000,000+.
      My test yesterday was from 10^1,000,000,000 to 10^1,000,000,000+1,000,000
      it took 9 minutes and 5 seconds to run the test. I was able to eliminate all but 9112 as being prime. That is using a small prime library of primes up to 1,000,000 approx.
      Just to make sure it is clear that is 10 to the 1 billion. Got a lot of questions about that on another forum.


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    • Phil Carmody
      ... From the speed, I can only assume you re running on a programmable calculator, or a PDA. NewPGen, which is notoriously inefficient for the initial ramp-up
      Message 2 of 4 , Jan 13, 2007
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        --- george hayes <gr.hayes@...> wrote:
        > I created a program that is testing for potential primes at
        > 10^1,000,000,000+.
        > My test yesterday was from 10^1,000,000,000 to 10^1,000,000,000+1,000,000
        > it took 9 minutes and 5 seconds to run the test. I was able to eliminate
        > all but 9112 as being prime. That is using a small prime library of primes up
        > to 1,000,000 approx.
        > Just to make sure it is clear that is 10 to the 1 billion. Got a lot of
        > questions about that on another forum.

        From the speed, I can only assume you're running on a programmable calculator,
        or a PDA. NewPGen, which is notoriously inefficient for the initial ramp-up of
        tiny primes can get to about 2 million in only a few seconds.

        And from your sieving depth, I'd have thought that about 72000 candidates
        should remain, so it sounds as if you have a bug.

        Phil
        Phil

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      • Jud McCranie
        ... He says that he is doing billion-digit primes.
        Message 3 of 4 , Jan 13, 2007
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          At 02:36 PM 1/13/2007, Phil Carmody wrote:

          >--- george hayes <<mailto:gr.hayes%40yahoo.com>gr.hayes@...> wrote:
          > > I created a program that is testing for potential primes at
          > > 10^1,000,000,000+.
          > > My test yesterday was from 10^1,000,000,000 to 10^1,000,000,000+1,000,000
          > > it took 9 minutes and 5 seconds to run the test. I was able to eliminate
          > > all but 9112 as being prime. That is using a small prime library
          > of primes up
          > > to 1,000,000 approx.
          > > Just to make sure it is clear that is 10 to the 1 billion. Got a lot of
          > > questions about that on another forum.
          >
          > From the speed, I can only assume you're running on a programmable
          > calculator,

          He says that he is doing billion-digit primes.
        • Phil Carmody
          ... No, potential primes . I can do that instantly by doing nothing. However, if I wanted to make use of a small prime library of primes up to 1,000,000
          Message 4 of 4 , Jan 13, 2007
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            --- Jud McCranie <j.mccranie@...> wrote:
            > At 02:36 PM 1/13/2007, Phil Carmody wrote:
            > >--- george hayes <<mailto:gr.hayes%40yahoo.com>gr.hayes@...> wrote:
            > > > I created a program that is testing for potential primes at
            > > > 10^1,000,000,000+.
            > > > My test yesterday was from 10^1,000,000,000 to 10^1,000,000,000+1,000,000
            > > > it took 9 minutes and 5 seconds to run the test. I was able to eliminate
            > > > all but 9112 as being prime. That is using a small prime library
            > > of primes up
            > > > to 1,000,000 approx.
            > > > Just to make sure it is clear that is 10 to the 1 billion. Got a lot of
            > > > questions about that on another forum.
            > >
            > > From the speed, I can only assume you're running on a programmable
            > > calculator,
            >
            > He says that he is doing billion-digit primes.

            No, 'potential primes'. I can do that instantly by doing nothing.

            However, if I wanted to make use of a "small prime library of primes up to
            1,000,000 approx.", then I'd probably sieve the range with that the, and I'd
            take something more comparable to a second than ten minutes.

            There's less than one thousandth of a prime in that range, and certainly zero
            provable ones even if there's one probable-prime.

            Phil


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