20150917, 00:22  #67  
6809 > 6502
"""""""""""""""""""
Aug 2003
101×103 Posts
2×5^{2}×173 Posts 
Quote:
You may want to check out Mersenne.ca e.g. http://www.mersenne.ca/exponent/brow...0001/332229999 Everything from 332192831 to 332459011 has been trial factored to at least the 74 bit depth (except those that have had a lower factor found). In the range to 332999959: Everything has been taken to 73 bits. Of those over 1,500 are at a depth of 77 bits or higher. Over 640 have had P1 factoring done on them. With P1 factoring, factors have been found in the range above 84 bits (many lower ones too) out to 106.9 (call it 107). We have found over 1200 factors that your program is not capable of finding. 

20150917, 00:30  #68 
If I May
"Chris Halsall"
Sep 2002
Barbados
3^{4}·5·23 Posts 

20150917, 00:57  #69  
6809 > 6502
"""""""""""""""""""
Aug 2003
101×103 Posts
2×5^{2}×173 Posts 
Quote:
I checked 332,290,807 (the next number with no known factor). It took Prime95 (32 bit version) 15 minutes to get through all bit levels up to (and including) 65, running on a single core on my 2.4 GHz Core2Duo laptop. Last fiddled with by Uncwilly on 20150917 at 01:03 

20150917, 01:16  #70  
"Forget I exist"
Jul 2009
Dumbassville
2^{6}×131 Posts 
Quote:
Last fiddled with by science_man_88 on 20150917 at 01:24 

20150917, 01:26  #71  
"Kyle"
Feb 2005
Somewhere near M50..sshh!
2·3·149 Posts 
Quote:
I found this claim very interesting especially considering bilirubin is widely considered in the medical literature to be neurotoxic particularly cases of kernicterus in newborns. I found a couple of papers that seem to support the idea of it acting as an antioxidant in the central nervous system involved in a redox reaction with biliverdin to prevent excess oxidation of lipids a parallel to the glutathione system that protects proteins from excess oxidation. At least one paper was in a fairly respected journal. I've not had the time to read the methods section yet. The cited sources are also interesting and may provide additional supporting evidence. The cited example of Gilbert Syndrome is especially interesting. That paper is cited from Atherosclerosis and indicates that these individuals have a 1/3 reduced incidence of cardiovascular events compared to the general population. I would like to read that paper as well when I find the time. I was also able to find a couple of papers that support at least in vitro evidence of antiviral activity of bilirubin at least against some herpes viruses and enteroviruses; however, it goes without saying that even good in vitro studies do not always translate well to in vivo studies. This will definitely require more reading! Thank you for this interesting bit of potentially paradigmchallenging information. Whether further research supports a physiologic and clinical significance for bilirubin's antioxidant effects remains to be seen but it is nonetheless intriguing. If anyone is interested I can provide names for some of the papers I found. A couple are free text articles while others require subscription to the journal itself or membership at an institution that provides access. Back to topic: I do not mean to disbelieve your good intents with your program; however, I would like to inquire as to why you have yet to answer these questions from Gordon. These seem like perfectly reasonable questions even if they are presented in a manner that could be perceived as mistrusting. If you have noticed these questions then your failure to address them is suspicious. If you have not noticed them before then here is your chance to address them. I won't pretend to know the significance of Madpoo's post about port 22. I will be the first to confess that I am ignorant when it comes to computer science, coding, and networks so ignorant, in fact, that I am almost assuredly using the wrong terms! Quote:
Last fiddled with by Primeinator on 20150917 at 01:26 

20150917, 02:05  #72 
"Carl Darby"
Oct 2012
Spring Mountains, Nevada
3^{2}×5×7 Posts 
The author of this software has either written his own ffts, is using some unknow new method to perform the squaring step of an LL iteration, or is exagerating the capabilities of his software. NVIDIA's ffts are capable of handling LL tests for Mersenne numbers up to around 200,000,000 decimal digits (as far as I can remember,) but definitely not 1 billion digit numbers.

20150917, 02:27  #73 
"Kieren"
Jul 2011
In My Own Galaxy!
271F_{16} Posts 
This exchange is fascinating.

20150917, 03:42  #74  
Serpentine Vermin Jar
Jul 2014
CCB_{16} Posts 
Quote:
To the program author: Check out a thread on here, the 100M benchmark discussion: http://www.mersenneforum.org/showthread.php?t=13185 My personal best is a time of 45 days for M332220523, but that's on a dual 14core Xeon with pretty good DDR4 memory. All 14 cores on CPU #1 and I think it was 45 cores on CPU #2 thrown in. There was someone else who did even better (I think) with a similar setup but dual 18core Xeons. If CEMPLLA could beat that, even on a "modestly priced $25,000 Nvidia times 5 system", you might be off to a good start. Remember though that not all Nvidia GPU's are equal. Besides requiring 5 of them (why 5?) you might also understand that some of the newer ones don't do so well at FP64. They'd be better suited to eliminating Mersenne #'s through factoring which they are still wicked awesome at. 

20150917, 04:06  #75  
Romulan Interpreter
Jun 2011
Thailand
2·13·337 Posts 
Quote:
The method you describe is EXTREMELY inefficient. Letting apart the fact that inventing your own notation scores high on the crankometer. There is a dedicated notation for all this stuff. For a first step, think about the fact that any possible factor of a mersenne number with an odd exponent can only be 1 or 7 (mod 8). As p is a prime (an odd prime), it can only be 1 or 3 (mod 4). Now, if k is 2 (mod 4), you get q=2*k*p+1, compute this (mod 8), for both cases when p=1 or 3 (mod 4). You will get q=2*2*(either 1 or 3)+1=(either 5 or 13) (mod 8) which is always q=5 (mod 8). So, k=2, 6, 10, 14, 18, 22, etc can NEVER occur in a q which is a factor of a mersenne number m=2^p1, for a prime p. By excluding k=2 (mod 4), which is one case in 4, your factoring program can be 25% FASTER. (now it is 33% slower, think about it! Like in forex trading, if you have $100 and lose $20, then you are 20% less, but now you have $80 and you will need to gain 25%, i.e. $20, to break even, percentages are odd ) Now again, you can continue splitting, if p=1 (mod 4), and k=1 (mod 4), you get q=2*1*1+1=3 (mod 8), another unacceptable case. If p=3 (mod 4), and k=3 (mod 4), you get q=2*3*3+1=19=3 (mod 8), another unacceptable case. So, you can DOUBLE the output of your factoring program by testing the modularity of p to 4 (which is extremely easy, just read the last two bits of the memory representation of your number) and if p=1 (mod 4), only test for k=3, 4, 7, 8, 11, 12, etc, i.e. k=0 or 3 (mod 4)  eliminating 50% of the cases, and if p=3 (mod 4), only test k=1, 4, 5, 8, 9, 12, etc, i.e. k=0 or 1 (mod 4), eliminating 50% of the cases also, from the start. Here you are, what George said that you can DOUBLE the output of your software, he was right, even if you didn't believe him. Try playing a bit with mfaktX on your GPUs. That program(s) in discussion take the "splitting" mentioned above and sieving to much higher levels, doing modularity not to 4 or 8, but to 420, or 4620 (why? can you tell what the reason for these numbers?), this way eliminating more than 95% of the "k" candidates. This way, they are already 20 TIMES FASTER than your factoring program even if they would run on the same hardware and even if they would not have another million optimizations. So, how can you compete? How can you convince us to use your program? Also (now playing the "credit whore" card!), everybody knows I am here for the credit and for the money, the first I get from GIMPS and the second  if I am lucky  I will get from George yarrrr... What do you offer to convince me to run your program, beside of a much slower progress and much higher electricity bill for me? (no, it is not rhetoric!) Last fiddled with by LaurV on 20150917 at 04:11 

20150917, 06:18  #76  
6809 > 6502
"""""""""""""""""""
Aug 2003
101×103 Posts
2×5^{2}×173 Posts 
Quote:
Code:
D:\prime\factor5win32win64src>factor5 3321928381 1 64 1 Factor5 v. 5.01  December 27th, 2007  Pentium4/Win32 compile  GMP 4.2.1_MPIR_1.0.0 Current date Wed Sep 16 22:49:32 2015 Factoring M3321928381 from 2^1 to 2^64 0.993% completed. Factoring M3321928381 from 2^1 to 2^64 7.537% completed. Factoring M3321928381 from 2^1 to 2^64 13.824% completed. Factoring M3321928381 from 2^1 to 2^64 20.221% completed. Factoring M3321928381 from 2^1 to 2^64 26.802% completed. Factoring M3321928381 from 2^1 to 2^64 33.309% completed. Factoring M3321928381 from 2^1 to 2^64 39.670% completed. Factoring M3321928381 from 2^1 to 2^64 46.287% completed. Factoring M3321928381 from 2^1 to 2^64 52.868% completed. Factoring M3321928381 from 2^1 to 2^64 59.486% completed. Factoring M3321928381 from 2^1 to 2^64 66.067% completed. Factoring M3321928381 from 2^1 to 2^64 72.611% completed. Factoring M3321928381 from 2^1 to 2^64 79.155% completed. Factoring M3321928381 from 2^1 to 2^64 85.736% completed. Factoring M3321928381 from 2^1 to 2^64 92.354% completed. Factoring M3321928381 from 2^1 to 2^64 98.935% completed. No factor found Performed 110261547 powmod operations since last restart. Used 110839 primes, max. prime = 1452991 Current date Wed Sep 16 22:57:12 2015 D:\prime\factor5win32win64src> Quote:


20150917, 06:45  #77  
6809 > 6502
"""""""""""""""""""
Aug 2003
101×103 Posts
21CA_{16} Posts 
Quote:
Quote:
How does your program stack up to that? BTW, the stats for my machine are posted above. Last fiddled with by Uncwilly on 20150917 at 06:46 

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