20210216, 06:39  #1 
"Tucker Kao"
Jan 2020
Head Base M168202123
563 Posts 
Getting others to do the work on exponents I like (was: Trial Factoring Progress)
I found a factor between 2^74 and 2^75 for M168,377,329 several minutes ago 
https://www.mersenne.org/report_expo...exp_hi=&full=1 M82,589,939 has a known factor too  https://www.mersenne.org/report_expo...exp_hi=&full=1 Any similarities can be observed between these 2 exponents? Last fiddled with by tuckerkao on 20210216 at 06:41 
20210216, 06:51  #2 
6809 > 6502
"""""""""""""""""""
Aug 2003
101×103 Posts
2^{2}×7×19^{2} Posts 
They are both known composites. As are the bulk of all Mersenne Number.

20210303, 03:43  #3 
"Tucker Kao"
Jan 2020
Head Base M168202123
563 Posts 
I believe I have figured out the assignment system by the trial factoring within Category 2 and 3. After I manually submit the results between 2^74 to 2^76, someone like curtisc will start to test the exponent I want with a faster PRP result 
https://www.mersenne.org/report_expo...exp_hi=&full=1 Last fiddled with by tuckerkao on 20210303 at 03:47 
20210303, 13:19  #4 
"TF79LL86GIMPS96gpu17"
Mar 2017
US midwest
2·11·269 Posts 
The P1 factoring done on https://www.mersenne.ca/exponent/108377323 is quite inadequate. It looks like curtisc has systems with prime95 default memory settings preventing stage 2 P1. Doing adequate bounds P1 the first time is efficient; doing stage1 only first or probabilityoffactorpercpuhour first, with or without a followup second factoring to adequate bounds to retire the P1 task, is not efficient. I'm running a cleanup P1 on that exponent now, which will complete in about an hour.
If you want to primality test yourself those exponents you begin with TF, immediately after reporting the TF to adequate bounds, request a manual PRP assignment for the same exponent, then adequately P1 factor it before beginning the primality test (PRP/GEC/proof). Last fiddled with by kriesel on 20210303 at 13:28 
20210306, 03:10  #5 
"Tucker Kao"
Jan 2020
Head Base M168202123
233_{16} Posts 
It seemed like that the chance of finding a factor only dropped by 0.0794% for not doing the trial factoring from 2^77 to 2^78 after the adequate P1 factoring conducted 
https://www.mersenne.ca/exponent/168374303 I finished the 2^78 bit on another exponent and didn't find a factor anyway, so unless someone really finds at least a factor between 2^77 to 2^80, I probably won't do the trial factoring further, just aiming for the direct PRP test. 
20210306, 03:55  #6  
Jun 2003
5,179 Posts 
Quote:
It seems like you're trying to rationalize not running deeper TF? I mean, it is your hardware, so do what you want, but you'll be better off in the long run by doing the recommended TF. Last fiddled with by axn on 20210306 at 03:55 Reason: quote 

20210306, 09:19  #7  
"Tucker Kao"
Jan 2020
Head Base M168202123
563 Posts 
Quote:
https://www.mersenne.org/report_expo...exp_hi=&full=1 So how likely will a factor between 2^77 to 2^78 skip the P1 factoring check? I ran the trial factoring from 2^77 to 2^78 for another exponent and that got my video card torched hot. I'd rather Viliam F perform this action if must needed. Last fiddled with by tuckerkao on 20210306 at 09:21 

20210306, 10:15  #8 
Jun 2003
5,179 Posts 
No, it isn't. The chance of a factor if you TF from 2^77 to 2^78 is 1/78 or 1.28%. The chance will be reduced if we're doing the TF after P1, but it will still be closer to 1% rather than 0.07% which is just nonsense.

20210306, 10:32  #9  
Jun 2003
5,179 Posts 
Quote:
So probability that TF will find a factor after P1 has completed is 1.28 (normal TF prob)  0.3868 (overlap prob) = 0.895% (or about 70% of the normal TF prob). This is the correct probability. 

20210306, 11:11  #10 
"Tucker Kao"
Jan 2020
Head Base M168202123
233_{16} Posts 
Looks like this is a personal preference ratio and may depend on each individual PC machines. It takes me 16 straight hours to run a trial factoring from 2^77 to 2^78, finish a PRP of the exponent that size will take me 28 days nonstop.
I have the liquid cooling for CPU but not GPU, the GPU couldn't run at its full speed if it's overheating. I don't know about the CPU and GPU speeds of Kriesel and Viliam's computers, but the ratio doesn't appear to save me time in the long run. Last fiddled with by tuckerkao on 20210306 at 11:13 
20210306, 12:32  #11 
Jun 2003
5,179 Posts 

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