20200823, 20:47  #1 
Aug 2020
162_{8} Posts 
How to make GMPECM skip stage 1 when feeding the prime95 results
I am basically following the method in this post, but it seems that GMPECM still runs stage 1 for a long time, which is already done by prime95, before doing stage 2 which it is good at. Does anyone know where the problem could be?
An example of the output: Code:
GMPECM 7.0.4 [configured with GMP 6.2.0, enableasmredc, enableopenmp] [ECM] Resume warning, skipping line with no '=' after: [Sun Aug 23 21: Resuming ECM residue saved with Prime95 Input number is 0x249C4CFAABA959C8705B51C84281F03253A8524BE39CFD8FDAA914BBF71E457C8C9F3417ABCF9C23E7F708B91D373F46A5EC530FB55C95FF69C98E03678FCAD94860EC429B1FBEB76854487C4BB6C655EDD9B94B38021E11A3BBDEC6F4EA30CA54DF94CD321F61 (248 digits) Using B1=44000000, B2=4400000000, polynomial Dickson(6), sigma=0:2856607019773923 Step 1 took 170265ms Step 2 took 3675ms Last fiddled with by Ensigm on 20200823 at 20:50 
20200824, 06:02  #2 
"Curtis"
Feb 2005
Riverside, CA
11001_{8} Posts 
Try setting B1 of 1, and let B2 be chosen by GMPECM. It's pretty pointless to use GMPECM for stage 2 while restricting B2 to 100* B1.

20200824, 09:20  #3  
Aug 2020
2×3×19 Posts 
Quote:
How to set B1=1 when resuming from the Stage 1 save file? I tried Quote:


20200824, 09:31  #4 
Aug 2020
2·3·19 Posts 
It seems that my version of gmpecm can make use of the savefile produced by itself, but not that produced by prime95. When it reads the prime95 savefile, it is able to recognize N and SIGMA, but seems to ignore the fact that stage 1 was already done.
The file produced by prime95 has 3 fields: N, QX, and SIGMA; The file produced by gmpecm has: METHOD=ECM, PARAM=0, SIGMA, B1, N, X, CHECKSUM, PROGRAM, Y=0x0, X0=0x0, Y0=0x0, WHO, and TIME. Last fiddled with by Ensigm on 20200824 at 09:39 
20200824, 11:00  #5 
Jun 2003
2·3^{2}·269 Posts 
Code:
ecm resume ecm_input.txt 44e644e6 > ecm_output.txt 
20200824, 13:35  #6 
Aug 2020
2·3·19 Posts 

20200824, 13:38  #7 
Aug 2020
2·3·19 Posts 
How to report the number of curves done by GMPECM
Now the second question: how do I report number of curves done using this method, if no factor has been found?

20200824, 14:23  #8 
P90 years forever!
Aug 2002
Yeehaw, FL
7^{2}×149 Posts 

20200824, 16:11  #9  
Aug 2020
114_{10} Posts 
Quote:
Thank you, but if there's not an automatic way then I'd rather not bother and waste the time of both of us. I don't have that much computing power to be worth doing it manually. Unless if I submit it like once half a year. Last fiddled with by Ensigm on 20200824 at 16:14 

20200824, 17:32  #10 
P90 years forever!
Aug 2002
Yeehaw, FL
7^{2}·149 Posts 
Yes, the few that do this kind of work, run 1000 curves or more and then email me.

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