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Old 2004-08-11, 10:54   #1
JFB
 
Jun 2004
France [UTC+2]

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Default over trial factoring

hello.

out of result.txt:
33,872,239 trial factoring up to 72
33,697,229 up to 70
34,004,779 up to 70
(these are only examples).

I've got 2 questions :
- is it done by manual overriding worktodo.ini ?
- is it worth factoring further 69 ?

thanks
JFB.
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Old 2004-08-11, 14:48   #2
PrimeCruncher
 
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Quote:
Originally Posted by JFB
hello.

out of result.txt:
33,872,239 trial factoring up to 72
33,697,229 up to 70
34,004,779 up to 70
(these are only examples).

I've got 2 questions :
- is it done by manual overriding worktodo.ini ?
- is it worth factoring further 69 ?

thanks
JFB.
It is done by using FactorOverride in either prime or local.ini (don't remember which). From the Prime95 help file on determining factoring levels:

Now the only question remaining is how much trial factoring should be done? The answer depends on three variables: the cost of factoring, the chance of finding a factor, and the cost of a primality test. The formula used is:


factoring_cost < chance_of_finding_factor * 2 * primality_test_cost


That is, the time spent factoring must be less than the expected time saved. If a factor is found we can avoid running both the first-time and double-check primality tests.
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Old 2004-08-11, 17:49   #3
JFB
 
Jun 2004
France [UTC+2]

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Thanks PrimeCruncher, I found FactorOverride parameter in Undocumented Features help.
But its purpose is to limit how far the program tries to factor a number,
not to go beyond Prime95 default settings.
Are you sure this is the way to deeper the factoring depth ?
Have you tested it ?
JFB.
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Old 2004-08-11, 17:55   #4
PrimeCruncher
 
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Quote:
Originally Posted by JFB
Thanks PrimeCruncher, I found FactorOverride parameter in Undocumented Features help.
But its purpose is to limit how far the program tries to factor a number,
not to go beyond Prime95 default settings.
Are you sure this is the way to deeper the factoring depth ?
Have you tested it ?
JFB.
I haven't tested it, no, but I believe that is the way to deeper factoring depths. I haven't seen anything else that would do that.
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Old 2004-08-11, 18:17   #5
ET_
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"Luigi"
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Quote:
Originally Posted by PrimeCruncher
I haven't tested it, no, but I believe that is the way to deeper factoring depths. I haven't seen anything else that would do that.
I tried it, and it worked fine

You can trial-factoring deeper with that option set.

Luigi
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Old 2004-08-11, 18:53   #6
JFB
 
Jun 2004
France [UTC+2]

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Thanks Luigi.
"This feature should not be used with the Primenet server" (Undoc.Feat.).
Did you encounter problem using it ?
JFB.
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Old 2004-08-11, 18:56   #7
PrimeCruncher
 
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Quote:
Originally Posted by JFB
Thanks Luigi.
"This feature should not be used with the Primenet server" (Undoc.Feat.).
Did you encounter problem using it ?
JFB.
It shouldn't be used with the PrimeNet server. It works fine for LMH (I have FactorOverride=62 set on my P3-850; it's working on the 58-58.5M range).
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Old 2004-08-11, 19:33   #8
JFB
 
Jun 2004
France [UTC+2]

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I don't understand, PrimeCruncher. Didn't you say you haven't tested it ?
Mmm... Maybe I'm too newB for that matter...
I will think about it some time.
Anyway thanks to both of you !
JFB.
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Old 2004-08-11, 19:34   #9
Prime95
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I don't think using that feature to factor deeper than normal will cause the PrimeNet server any grief.
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Old 2004-08-11, 20:05   #10
JFB
 
Jun 2004
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I take it from whom it comes from !
Il ne faut pas ĂȘtre plus royaliste que le Roi.
Thank you Georges.
JFB.
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Old 2004-08-11, 21:06   #11
Axel Fox
 
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If I'm not mistaking (and correct me if I'm wrong, George), the FactorOverride parameter is ignored when you use PrimeNet. If "Use Primenet" is unchecked, the program will factor from the number in the worktodo.ini file to the FactorOverride parameter (or to the standard value if FactorOverride is not set).

So, if "Use Primenet" is checked, it always factors to the standard value.
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