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Old 2020-12-26, 10:21   #1
pepi37
 
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Default Prime 95 P-1 method B1 and B2

I use P-1 with Prime95 to find some factors. Since my candidate reach near 3M digits, I decide to go little deeper with P-1 and now I save P-1 files.
So current B1=100000 and B2=1000000

Question: if I reuse P-1 file from those B1 and B2 limits what is new B1 and B2 limit I can make

option a B1=200000 B2=2000000
option b B1=1000000 ( continue from "old" B2 limit) and B2 like 5000000

Thanks for any advice!

Last fiddled with by pepi37 on 2020-12-26 at 10:37
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Old 2020-12-26, 17:54   #2
ixfd64
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Unfortunately, no. If you want to change your B1 value after starting the second stage, then you'll have to start the whole thing over.
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Old 2020-12-26, 18:53   #3
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Quote:
Originally Posted by ixfd64 View Post
Unfortunately, no. If you want to change your B1 value after starting the second stage, then you'll have to start the whole thing over.
So I can rerun with same file and expand B2 bound?
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Old 2020-12-26, 20:03   #4
ixfd64
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Yes, you can extend B2 as long as you don't change the B1 value.
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Old 2020-12-26, 20:22   #5
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Quote:
Originally Posted by ixfd64 View Post
Yes, you can extend B2 as long as you don't change the B1 value.
Thanks, very useful info, part I missed!
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Old 2021-01-04, 03:47   #6
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"James Heinrich"
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Last fiddled with by James Heinrich on 2021-01-04 at 03:48 Reason: redacted for not reading original post properly
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Old 2021-01-04, 06:07   #7
LaurV
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P95 does NOT extend B1/B2 properly. If you do a run with some B1/B2 then try to extend B1 (with or without extending B2), then you either need to run everything from scratch, or you may miss factors, depending on what combination of extensions you do. This happens WITH all the files saved properly (I don't talk about the case when you don't have the file from the first run, that case is obvious that you need to run everything from scratch). This was discussed before on the forum, and I don't think is fixed. If you want to extend B1, then P95 should only consider the prime powers fitting between LCM(B1) and LCM(B2), which it doesn't.

Last fiddled with by LaurV on 2021-01-04 at 06:13
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