20031130, 23:26  #12  
Aug 2002
2^{2}×5×13 Posts 
Ethics in choice of DC project
I will not delve deeply into the ethics of running this or that DC project. I would like to quote a post, from the ARS Distributed Computing Arcana thread, Ethics? Why spend YOUR spare cpu cycles on seti rather than cure cancer ?, that echoes my feelings on the subject very well: Quote:
Everyone has the right to make his or her own decisions about running a particular Distributed Computing project. I can tell you that I, with my whole heart, believe it is a worthwhile project for this or that reason, how wonderful the work we are doing is, how really nice the people and the community are, how knowledgeable and helpful they are, and so on. Unless you have or can find a reason you believe in it, then you should think twice about running any Distributed Computing projects that require a voluntary effort on your part. Last fiddled with by Prime Monster on 20031201 at 01:12 

20031130, 23:28  #13 
Aug 2002
260_{10} Posts 
Why donate your computer cycles to GIMPS?
I included the following text in its entirety because I though it was one of the best personal arguments that I have ever read about why one should participate in GIMPS. Enjoy !!! Originally posted by Lumly I could give you technical reasons for crunching for GIMPS, but I won't. Most people aren't interested in them, though they exist and are quite persuasive. I find the psychological reasons far more compelling because, in the end, these are the reasons you will stay with the project. Tell me something I don't know. There is something very gratifying about knowing the actual outcome of your work unit. A GIMPS client returns very definite results. If you trial factor an exponent successfully, it will not only tell you so but give you the factor that it found. If you LucasLehmer test an exponent, you will know that it is, or isn't, prime because it actually tells you. Results are forever. You can always refer back to them at any time. Twenty years down the road you will be able to state with certainty that you proved that suchandsuch a Mersenne number was composite. This is not the case of most other distributed computing projects. You will never have a screen that pops up and tells you that you just found E. T. You will endlessly process work unit after work unit and never will you be able to distinguish between the first one and the tenthousandth. Anthropomorphic personification. Crunching for distributed computing projects can be thrilling. Watching the number of work units you put out per day can make you excited about your throughput. The work pours in quickly and the results leave even faster. GIMPS is a different sort of project for it is slow and deliberate. The work units are so unlike most others projects’ that we don't even call them work units at all. We call them exponents or assignments because the term ‘work unit’ isn't personal enough. With today’s computers these exponents can take anywhere between two days to two months to complete. Running a LucasLehmer test on a 33M (a LucasLehmer exponent that is in the thirtythree million range or, when expanded, is a ten million digit number) is an intimate process. You will probably have to trial factor it. Then it passes into P1 factoring stage 1, on to P1 factoring stage 2, and finally it spends weeks on the LucasLehmer testing. All the while you watch it slowly mature. The exponent ceases to be a mathematical representation of an integer but instead takes on a life all its own. It is a life that you and your computer nourish with CPU cycles. Even though you know that only a tiny fraction of the LucasLehmer test could possibly have been performed, you check on it several times a day just in case something goes wrong. You get to know it like a friend. You can recite it by number and you remember it long after the result of the test has been sent in to Prime Net. No other distributed computing project comes close to this level of emotional attachment for the cruncher. The time invested on each exponent is what makes GIMPS special. It teaches the user patience and perseverance. Devotion and loyalty soon follow. It’s quiet... too quiet. Another unique aspect of GIMPS is that you can use the client program to search for prime numbers completely on your own. You do not have to go through the server to get your assignments, nor do you have to use the manual web pages. You can, at any time, test any exponent that you wish. The results will be reported to you in the normal fashion, at which point you simply test another one at your leisure. This allows you to do your own search, testing your own range of exponents, building up your own data sheet of results with no one else the wiser. You can be like the mathematicians of old, working in solitude, hoping to find that one number that will put them in the history books. Should you find a one, you will be accredited, along with the project programmer who after all did write the application. Alas, Horatio, I knew him well. The greatness of a distributed computing project isn't dependant on the kind of work it researches, but rather the quality of its client program. This is in turn influenced solely by the competence of the programmer behind it. Some distributed computing projects have client programs that are rarely updated, or worse still, that are rewritten by the users because the programmer himself is not talented enough to handle the job. GIMPS’ George Woltman is a singular man in this respect. Easily reachable by any and all who want to talk to him, he listens to the needs of his crunchers. He continually seeks to optimize the client’s code, often rewriting it completely for every new instruction set that is released. If a bug is found then it is fixed. If you have a suggestion then he will listen. He just plain takes the time and effort. All of this is because he is passionate about prime numbers. It has forced him to learn his maths as well as his programming. It is this infectious zeal that spreads to those who crunch for GIMPS. You don't need to know just how it works. When you see the amount of energy he puts into it, you are hard pressed not to want to share in it. We regret to inform you ... Many people have had high aspirations when they were young. Just how many wanted to be a fireman or a ballerina but never did can never be known. My own ambition was to go into astrophysics. Along the way I discovered that although my algebra was top notch I just couldn't wrap my head well enough around calculus. That failure is a regret that I have, and though the search for prime numbers does not entail the direct use of calculus nor does it solve the meaning of the universe, the chance to work on a problem of purely mathematical abstraction without the need to train oneself for years is appealing to me. ...these fifteen... no ten, ten commandments! Probably the most compelling reason to run GIMPS is to get your name in the history books. Think of it. Mersenne himself lived and died hundreds of years ago and yet today his name is plastered all over an electronic medium of which he could never even have conceived. All the discoverers of Mersenne primes have their names permanently etched in ‘stone’, and although no one will remember most of their names from memory, they will still be there in the list, flagstones on the never ending path of mathematical discovery. Thousands of years from now their names will still be recorded somewhere as discoverers of Mersenne primes. This is no exaggeration either. As long as modern technology survives, so will their names. You will never find this sort of reward in other distributed computing projects. Hundreds of years from now no one will record the fact that it was your computer that found the key fold of a protein. No one will record that it was your computer that processed the signal that found extraterrestrial life. All that will be recorded is that it was a group effort. Mathematical research differs in this respect. It is a tradition to credit the individual. In fifty words or less... Idle hands are the devil’s playground, as too are idle CPU cycles. If you are still reading this then you must agree. The only choice left is where to put your allegiance. Please consider joining GIMPS today. Written by Justin "Lumly" Valcourt Last fiddled with by S485122 on 20100406 at 05:04 Reason: it is P1 factoring not L1 factoring 
20031130, 23:29  #15 
Aug 2002
2^{2}·5·13 Posts 
More on Distributed Computing
The combined processing power of all the computers in the world is astonishing. The vast majority of these computers never utilize anything but a small fraction of their computational power. The rest of the processing power remains unused and under ordinary circumstances goes to waste as socalled idle cycles. Surfing the Web, checking email, using Word and Excel does not exert much pressure on a modern processor that can operate at many hundreds of million instructions per second. Most of the time, the processor sits idle, waiting for something to do. It doesn't actually do anything, but performs a special operation that  well does nothing. This cycle is called an idle cycle. There are a number of individuals or groups in the fields of science, mathematics, cryptography, and other fields who require massive amounts of computing power in order to solve certain problems. In many instances, the cost of the highend computers that would be required in order to solve these problems is far too high for these researchers, or for very rich companies or even governments. There are instances where the total required computing power to solve a problem is so high that it is not realistically obtainable at all. Many of these problems have important implications for fields such as medicine, mathematics and other scientific areas of exploration and could benefit humanity in general if solved. This is where Distributed Computing comes into the picture. Using the unused computing power of a large number of computers some of these problems can actually be solved within a reasonable amount of time. Distributed Computing (DC) is a branch of Computer Science that deal with ways one can solve these large computational problems. Large computing tasks are first broken into much smaller tasks (often called Work Units or WUs), which are then sent over the Internet to lots of smaller computers for processing. These smaller work units are then processed utilizing only the unused computing cycles or idle cycles. When a computation unit is completely processed, the result is then uploaded to a central server which has the responsibility of storing the results and do any postprocessing if necessary. The computational units are designed so that the amount of data that needs to be downloaded and uploaded is kept small in order to avoid overburdening the user's Internet capabilities. The central server sorts and arranges the data received in such a way that the processed data points combine in order to effectively function as if all the entire problem was processed in one extremely powerful computer. The whole process turns an individual's computer effectively into a small part of a giant supercomputer whose different parts are connected through the Internet. This technique allows researchers inexpensive access to massive computing power that would not otherwise be obtainable. By running one of these distributed computing projects, you can play an important role in solving one of these computational problems. Last fiddled with by Prime Monster on 20031201 at 19:25 
20031130, 23:29  #16 
Aug 2002
2^{2}×5×13 Posts 
How to Sneakernet the client
To sneakernet (nonet or offline work) or move work in progress around various machines, follow this procedure: The prime95 client structure is quite simple. There are 5 basic files that are in use: prime.ini local.ini worktodo.ini prime.spl checkpoint files: p123456, q123456 and pl123456 The first two checkpoint files are LL tests (one is a backup, to nonet only one is needed) and the last one is for factoring work Optionally, copy results.txt and prime.log if you want to see what was going on while the work crunched. The safest way to handle sneakernetting is to install each instance in a unique directory and configure it as such with its own userid. Start up the client, get the amount of work required (keeping in mind you must make an update within 60 days maximum) and then stop it. Zip the above files to move them to the new target install. On the target box, install the client as torture test only. This ensures that there will be no confusion, as all the info required is found in local.ini and prime.ini. Alternately, the entire client can be copied over from the source box. prime.spl may or may not be present depending on the work type and settings. It contains the results (and unsent messages to the server). If it exists, do not let it and the checkpoint files become unsynchronised. To dump a box, stop the client and keep it stopped until you return with fresh work. Then, it will pick up exactly where it was last stopped on the exponent in progress. When returning to the nonet box you must delete the old prime.spl (and checkpoint files if you had run the exponent for any period of time on the master box, otherwise do not copy back the checkpoint file as it will not be needed). For nonet computers it is desirable to minimize the number of communication attempts. Set the send new end dates in options / preferences to 58 days and set the network retry to 300 minutes. Set the cache option to 1 day to prevent the client from attempting to get more work. Last fiddled with by Prime Monster on 20031201 at 02:49 
20031130, 23:30  #17 
Aug 2002
2^{2}×5×13 Posts 
Why participate in the GIMPS project
Note: A lot of the text here is copied from Dr. Chris K. Caldwell's  Why do people find these primes? Tradition! Euclid may have been the first to define primality in his Elements approximately 300 BC. His goal was to characterize the even perfect numbers (numbers like 6 and 28 who are equal to the sum of their aliquot divisors: 6 = 1+2+3, 28=1+2+4+7+14). He realized that the even perfect numbers (no odd perfect numbers are known) are all closely related to the primes of the form 2^{P}1 for some prime P (now called Mersennes). So the quest for these jewels began near 300 BC. Large primes (especially of this form) were then studied (in chronological order) by Cataldi, Descartes, Fermat, Mersenne, Frenicle, Leibniz, Euler, Landry, Lucas, Catalan, Sylvester, Cunningham, Pepin, Putnam and Lehmer (to name a few). Much of elementary number theory was developed while deciding how to handle large numbers, how to characterize their factors and discover those which are prime. In short, the tradition of seeking large primes (especially the Mersennes) has been long and fruitful. It is a tradition well worth continuing. For the byproducts of the quest Being the first to put a man on the moon had great political value for the United States of America, but what was perhaps of the most lasting value to the society was the byproducts of the race. Byproducts such as the new technologies and materials that were developed for the race, are now common everyday items. The same is true for the quest for record primes. In the tradition section above are listed some of the giants who were in the search (such as Euclid, Euler and Fermat). They left in their wake some of the greatest theorems of elementary number theory (such as Fermat's little theorem and quadratic reciprocity). More recently, the search has demanded new and faster ways of multiplying large integers. In 1968 Strassen discovered how to multiply quickly using Fast Fourier Transforms. Strassen and Schönhage refined and published the method in 1971. GIMPS now uses an improved version of their algorithm developed by the long time Mersenne searcher Richard Crandall. The Mersenne search is also used by school teachers to involve their students in mathematical research, and perhaps to excite them into careers in science or engineering. People collect rare and beautiful items Mersenne primes, which are usually the largest known primes, are both rare and beautiful. Since Euclid initiated the search for and study of Mersennes approximately 300 BC, very few have been found. Just 40 in all of human historythat is rare! But they are also beautiful. Mathematics, like all fields of study, has a its own notion of beauty. What qualities are perceived as beautiful in mathematics? Mathematicians look for proofs that are short, concise, clear, and if possible that combine previous disparate concepts or teach you something new. Mersennes have one of the simplest possible forms for primes, 2^{P}1. The proof of their primality has an elegant simplicity (to a mathematician). Mersennes are beautiful and have some surprising applications. For the glory! Why do athletes try to run faster than anyone else, jump higher, throw a javelin further? Is it because they use the skills of javelin throwing in their jobs? Not likely. More probably it is the desire to compete (and to win!). This desire to compete is not always directed against other humans. Rock climbers may see a cliff as a challenge. Mountain climbers can not resist certain mountains. Look at the incredible size of these giant primes!, like the currently Largest Known Prime. Those who found them are like the athletes in that they outran their competition. They are like the mountain climbers in that they have scaled to new heights. Their greatest contribution to mankind is not merely pragmatic, it is to the curiosity and spirit of man. If we lose the desire to do better, will we still be complete? Athletes do not only compete as individuals, but also as teams or groups of individuals, with the same desire to be first and best. In the same manner, so to speak, can prime searchers compete in teams, like ARS Team Prime Rib. As with other competitions we closely follow our standing against other teams and rejoice over any gain we make. To test the hardware This one has historically been used as an argument to get the computer time, so it is often a motivation for the company rather than the individual. Since the dawn of electronic computing, programs for finding primes have been used as a test of the hardware. For example, software routines from the GIMPS project were used by Intel to test Pentium II and Pentium Pro chips before they were shipped. So a great many of the readers of this page have directly benefited from the search for Mersennes. Slowinski, who has found more Mersennes than any other, works for Cray Research and they use his program as a hardware test. The infamous Pentium bug was found in a related effort as Thomas Nicely was calculating the twin prime constant. Why are prime programs used this way? They are intensely CPU and bus bound. They are relatively short, give an easily checked answer (when run on a known prime they should output true after their billions of calculations). They can easily be run in the background while other "more important" tasks run, and they are usually easy to stop and restart. Intel uses just a few iterations of prime95 to test the FPU. Obviously, they incorporated part of the code in their test program rather than running prime95 directly. This is only one of many tests  but it's a good one. OverClockers often use programs like Prime95 and SuperPi to test the stability of systems. If the system can run the Prime95 and SuperPi programs for any length of time without failing, they are regarded as stable. To learn more about their distribution Though mathematics is not an experimental science, mathematicians often look for examples to test conjectures (which they then hope to prove). As the number of examples increase, so does (in a sense) their understanding of the distribution. The prime number theorem was discovered by looking at tables of primes. For the Challenge Why do anything, why climb that rock, why read that book, why learn a new language, why build a machine ? On the whole there are a lot of why do questions. And they can all, although not always, be answered with: For the challenge of doing it and because it can be done. Mankind seems to have, this need to overcome challenges built into them from the start. We are always pushing borders and limits. I believe the answer to the question raised above, "If we lose the desire to do better, will we still be complete?", is no. We need the desire to do it, to overcome the challenge. Last fiddled with by Prime Monster on 20031201 at 19:36 
20031130, 23:30  #18  
Aug 2002
2^{2}×5×13 Posts 
What now?
So, having read all or some of these post, followed some or all of the links, thought long and hard, you decided to stop wasting idle CPU cycles and participate in GIMPS. What now? The first thing to do is to go back to How to get started with GIMPS, download and install the program, start it, follow some simple instructions and you are part of GIMPS. Then, I suggest, you sign up for mersenneforum.org, come along and join the fun. You can find a lot of interesting GIMPS stuff there, but not only that. If you are interested in the software or the hardware used to run the project, you will find that is covered in the forums, along with puzzle solving, programming, Linux, math, tweaking computers and lots of other subjects. In general I hope you will find us a friendly, interesting and helpful bunch of fellow travellers. To quote a forum member ixfd64 (slightly edited by me): Quote:
Another thread you might find useful is the Glossary for the slang impaired Please help out! where some of the terms from this text are explained. Good prime hunting Last fiddled with by Prime Monster on 20031201 at 19:37 

20040529, 13:08  #20 
Aug 2002
2^{2}×5×13 Posts 
The 40th Mersenne Prime!
The 40th Mersenne Prime!
If you came here just to find out about this new Mersenne Prime number then here are the bare facts. The newly discovered Mersenne Prime number is 2^{20996011}1, or 2 to the 20,996,011th power minus 1. It was discovered by Michael Shafer, on 17Nov03 19:04, using prime95 on his office computer. He used a 2 GHz Pentium 4 Dell Dimension PC running for 19 days to prove the number prime. The new prime was independently verified by Guillermo Ballester Valor of Granada, Spain using twelve days of time on a 1.4GHz quad Itanium II server at the HP Test Drive center, and by Ernst Mayer of Cupertino, California using three weeks of time on a 1 GHz HP Alpha workstation. Michael Shafer a chemical engineering student at Michigan State University used his office computer to contribute spare processing power to the Great Internet Mersenne Prime Search. Why, you may ask, do you have to verify the Mersenne prime using a different client? There is no difference in the math between the clients. Both implement a LucasLehmer primality test using discrete weighted transforms. Prime95 was written in x86 assembly code. Glucas is written in C code. Since the clients were written by different people and run on different hardware, that virtually eliminates a programming bug or hardware flaw as a cause for a false M40 report. Some trivia about the 40th Mersenne Prime! The new Mersenne, 2^{20996011}1 has 6,320,430 decimal digits, and is currently the largest known prime number. If I were to post it here, then it would fill, using 25 post per page, 10.000 characters per post, 25 and some pages. If you printed it out in one continuos line using a 12 point font then the line would be ... 26,755km (16.624 miles) long without commas, and 35,675km (22.167 miles) long with commas. (Worked out by extrapolation from length of the previous one). Other places to read about the new Mersenne
This list is continues in A list of online references to M40. I will try to keep it reasonably updated. Last fiddled with by Prime Monster on 20040529 at 21:28 
20191223, 15:31  #21 
6809 > 6502
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Aug 2003
101×103 Posts
5×2,179 Posts 
A whole reference material section:
https://www.mersenneforum.org/showthread.php?t=24607 
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