Re: Mersenne: idea for a new prime95 version
At 01:50 AM 2/4/01 -0600, Steve wrote: There are so many screensavers available now that one can be found to match any personality, Why not identify a couple of existing screensavers that could be "compatible" with Prime95 and then approach the author(s). ask them to make a verion that includes George's stuff? --Luke _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: idea for a new prime95 version, QA, primenet etc
On 3 Feb 2001, at 17:03, Jeff Woods wrote: With increasing exponent size (and therefore run time), I'd like to see PrimeNet evolve to track intermediate residues also to be able to coordinate parallel LL testing double-checking, so that runs which are going wrong can be stopped for investigation without having to be run through to the end. I think this is an EXCELLENT idea, but remember that the "s" values (i.e. the intermediate residue/modulus) for such numbers is quite simply enormous. One couldn't (and shouldn't) check the entire intermediate value, but merely the last "x" bits, where "x" is enough to be reasonably certain that a match isn't random chance -- say, the final 1024 bits. 64 bits is enough to be pretty confident! We need a recovery procedure anyway, to cope with any systematic bugs which may exist. PrimeNet would thus also have to carefully assign the exponents to similar machines with similar runtimes and performance, as it would do little good to assign the primary test to an Athlon-800 and the "real-time" double-check to a much slower machine, as the Athlon would quickly outpace the second check. If a discrepancy was found in a real-time double-check, a ternary run on a different machine could determine which (if either) of the two intermediate residuals was correct, and the tests could proceed from there, with both original machines assuming the same correct residue. My reply to Ken Kriesel's message on this topic shows how the need for paired systems to be evenly matched could be avoided - though it is certainly preferable that gross mismatches are avoided. However, there shouldn't be much problem providing reasonable matches, since the PrimeNet server knows each participating system's CPU type clock speed. Also, if this did evolve, I'd suggest that the "double-checker" be given equal credit with the primary machine, for purposes of credit in history books as discoverers, and/or EFF monies. This question obviously needs to be addressed, if only to keep lawyers out of our hair. I agree with Jeff on this one. Note that there's a point of futility, at which a "tie-breaker" ought to merely be a triple-check, run to conclusion. Let's say on a 14-month co-op effort, 13.6 months into it a discrepancy was found. Both machines ought to finish, and just have it triple-checked, rather than suspending both, awaiting a tiebreaker. While I'm sure someone could solve for the optimum cutoff point where tiebreakers are not useful, my guess would be that it is around 85% of the way to completion. With the suggestions in my reply to Ken, having "late" checkpoints doesn't do much to slow down completion - the leading system proceeds unless or until the trailing system finds a discrepancy. However, I certainly agree that there's not much point in having a checkpoint at iteration 14 million if you're testing e.g. exponent 1403. I'd suggest "missing out" the last checkpoint if the number of iterations remaining at that point is less than half the iterations between checkpoints. Regards Brian Beesley _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: idea for a new prime95 version
On 4 Feb 2001, at 1:50, Steve wrote: "Alexander Kruppa" wrote: The screen-saver idea is important for another reason. I asked several coworkers and secretaries to let Prime95 (NTprime, actually) run on their PCs and they agreed, but they were less than happy when I asked them to change the pretty 3-d screen savers for something that lets NTprime have more cpu power. With the selection Microsoft offers right now, that means "Blank Screen" or "Marquee" - neither is extremely exciting to watch. Before long, most of them went back to the old screen savers and NTprime slowed down to a halt. "...slowed down to a halt" is no exaggeration. I've seen screensavers slow it down to more than 7 seconds per iteration at 800+ MHz. I have it running on some PCs where the user has the screensaver set to start after 5 minutes then sets the power management so the monitor turns off after 10 or 15 minutes... and what really bothers me is that the screensaver continues to run even with the monitor off. (Is there some way to prevent that which I don't know about?) Not that I'm aware of, either. You're supposed to use ACPI to make the processor sleep rather than worry about details such as whether the screensaver is still running with no visible display. One idiot even had her settings such that the screensaver didn't start until _after_ the monitor went off. No accounting for stupidity! I wonder if you could get away with tricking users like this into staring at the "blank screen" saver for hours on end by fooling them that, very occasionally, something "interesting" happens? ;- There are so many screensavers available now that one can be found to match any personality, and I have found it impossible to get people to let go of one they really like. So I don't believe Brian's idea will do very much good; but then every little bit helps. Could I respectfully point out that the windoze screensavers run at priority 4. If you raise Prime95/NTPrime's priority to 4, you will split CPU time more or less evenly between the screensaver and the Mersenne client. In fact there should be a bit more going our way than the screensaver does; the screensaver does voluntarily relinquish the CPU occasionally - otherwise a client running at priority 1 would get nothing. On the principle that half a system is better than nothing, this trick is probably worth publicising, if it will let users keep their favourite screensaver running. I'd warn strongly against raising the priority of Prime95/NTPrime any higher than 4, as there could be serious consequences to the performance of foreground tasks. BTW, and getting way off topic, on windoze I use a freeware gadget called Sleeper which I downloaded from the net ages ago. Still works on Win2K though. This has "hot spots" in two corners of the screen (configurable in size and which two corners are used); if you park the mouse pointer in one of the "hot spots", the screensaver activates "immediately" (actually there is a 2 sec delay) whilst parking the mouse pointer in the other "hot spot" prevents the screensaver from ever activating. If the mouse pointer is elsewhere, the screensaver activation is normal (as if Sleeper were not present). I use this (in conjunction with the screensaver password feature, and the standard "blank" screen saver) as a security tool, to lock access to my system through the console when I'm temporarily absent e.g. gone for a leg stretch. Obviously you need to set the BIOS boot setup passwords as well, to prevent people from breaking in by simply resetting the system. And, no, it isn't perfect, but then no security system is. The "never activate" feature is also useful, as it prevents screensaver activation from interfering with tasks like scandisk and defrag which don't take kindly to anything happening which causes the volume being processed to be accessed. Sleeper is tiny and has no detectable processing time overhead. Obviously it does need to steal a few cycles, but it really isn't significant, even on a slow system. Regards Brian Beesley _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: idea for a new prime95 version
Steve wrote: "...slowed down to a halt" is no exaggeration. I've seen screensavers slow it down to more than 7 seconds per iteration at 800+ MHz. I have it running on some PCs where the user has the screensaver set to start after 5 minutes then sets the power management so the monitor turns off after 10 or 15 minutes... and what really bothers me is that the screensaver continues to run even with the monitor off. (Is there some way to prevent that which I don't know about?) One idiot even had her settings such that the screensaver I have to agree here. I installed Prime95 on my parent's computer, and took it off again after I found out the screen saver keeps going after windows turns the monitor off (3D flowerbox or something like that). I guess I overestimated microsoft's intelligence when I actually expected the screen saver to quit after the monitor was blanked (end eventually turned off). Is there any way somebody could modyfy this behavious? Marcel -- "'Chapter Fifteen, Elementary Necromancy'", she read out loud. "'Lesson One: Correct Use of Shovel...'" Terry Pratchett, Jingo _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: idea for a new prime95 version
"Brian J. Beesley" wrote: On 4 Feb 2001, at 0:27, Alexander Kruppa wrote: Well, you could bump NTprime's priority to 4; that would let NTprime steal CPU cycles off the screensaver, without being too obvious to the user :) Don't go any higher, as you would risk seriously impacting the performance of foreground tasks. One big point you can use to convince coworkers/managers etc is that Prime95 only uses cpu time that no other process wants. Most everyone I asked wanted explicit confirmation that Prime95 does not take cpu time while other processes are running. I can just see them frowning at me when I say that Prime95 will now steal only such a little amount of cpu time.. No, I think Prime95 really should run at idle priority. With the selection Microsoft offers right now, that means "Blank Screen" or "Marquee" - neither is extremely exciting to watch. Before long, most of them went back to the old screen savers and NTprime slowed down to a halt. Does that mean that the primary purpose of the computers used by your coworkers is to provide a colourful distraction? Putting a picture on a wall in an office is not the primary purpose of an office either, yet most everyone I know does it. Everyone can set up his workplace the way he wants it. I can't go and tell them what to do with their computers, I was happy enough when they agreed to let me install a strange piece of software. If they like colorful displays then why shouldn't they have them? The solution would be to write a screen saver that is pleasing to look at (and not just for tech dweebs) and yet leaves enough cpu time for an idle-priority background process. I suppose you could try fibbing that something interesting happens occasionally in the blank screen (like the teapot in the 3D pipes saver), and see how long you can make them stare at it ;- Regards Brian Beesley How about a cute kitten that sleeps for hours, wakes up, stretches, walks to another corner of the screen and sleeps some more? 99% static graphics, has the "oh sweet!!" bonus and people will try to leave the computer alone as not to disturb the kitten while Prime95 happily crunshes away :) Ciao, Alex. _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: idea for a new prime95 version, QA, primenet etc
Nothing built by human hands is perfect, so, sure, the program could be improved! Personally I'd like to see an optimization for Athlon; at the expense of having to load different versions for different processor types, I'd like to see seperate "streamlined" versions of the code optimized for different processor types rather than one monolithic program with everything embedded in it; Optimizations for Athlon would be very welcome :) Using a modularized version of the program (sort of like dll's) would keep the simlicity in using the program AND keep it resource-efficient. The added download time shouldn't be a problem since it is a one-time download and for example SETI@Home requires daily downloads on a fast machine. (That project isn't going all to bad :)) just my two cents... /Lars _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: idea for a new prime95 version
Idea for a screensaver for Prime95, let the user specify a directory of picture files and Prime would pick one to display every few minutes. Decoding a JPG or GIF would suck up some cycles but between picture updates Prime would get them all. Cheers... Russ _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: idea for a new prime95 version
On 3 Feb 2001, at 7:18, mohk wrote: Win32Prime would be the correct name to use there since the name reflects what platform it runs on. I guess Prime95 comes from the "good old days" when Win95 was new and unqualified program names were expected to be 16-bit Win 3.x applications. BTW there still is a Win 3.x version of this program - I wonder if anyone's still using it??? But my vote's _against_ changing the name just for the sake of tracking fashion. What the program does is far more important than its name. We also have to bear in mind that some of the more obvious names have been picked up by other programs. (It seems we need a new prime or nice milestone now. The list is virtually dead :( ) OK, go find us one ;-) I thought a voting creates a new discussion, about increcements, odds etc. C'mon ppl, wake up and give a comment about improving the prime95 proggi. We need to remember what the function of the program is. It's designed to run unobtrusively in the background, and to have a low administrative overhead (be easy to set up, and easy to maintain). From this point of view, the existing program does an excellent job, it's really hard to see how it could be significantly improved. George has announced the development of new FFT code optimised for Pentium 4. The FFT code is the true heart of the program: it's really hard for me to put into words just how much we all owe to George for his unstinting efforts to make the program as efficient as it is. Suffice it to say that, without George's input, we would probably be two or three Mersenne primes short of where we actually are. Nothing built by human hands is perfect, so, sure, the program could be improved! Personally I'd like to see an optimization for Athlon; at the expense of having to load different versions for different processor types, I'd like to see seperate "streamlined" versions of the code optimized for different processor types rather than one monolithic program with everything embedded in it; and I'd like to see the client/server security code somehow "opened", to facilitate the integration of non-Intel clients into PrimeNet, but without sacrificing the trust we have that results have really been computed. With increasing exponent size (and therefore run time), I'd like to see PrimeNet evolve to track intermediate residues also to be able to coordinate parallel LL testing double-checking, so that runs which are going wrong can be stopped for investigation without having to be run through to the end. Some people have indicated they'd like a version of the program with a pretty screen-saver interface. Fair enough, provided we can keep the "classic" version without the extra overhead. Probably the easiest improvement to make is to have the documentation translated into some other languages; unfortunately I can't help here, as my command of languages other than English is very poor. However, having a copy of README.TXT and the explanatory web pages available in one's own native language would almost certainly help to popularise the program worldwide. I'm thinking of (in no particular order) French, German, Spanish, Japanese - and Chinese, if there is a variant which is standard enough to be useful. Please excuse my ignorance on this last point. And, of course, any other language for which we can find a willing translator :-) Regards Brian Beesley _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: idea for a new prime95 version, QA, primenet etc
At 09:23 AM 2/3/2001 -, "Brian J. Beesley" [EMAIL PROTECTED] wrote: George has announced the development of new FFT code optimised for Pentium 4. The FFT code is the true heart of the program: it's really hard for me to put into words just how much we all owe to George for his unstinting efforts to make the program as efficient as it is. Suffice it to say that, without George's input, we would probably be two or three Mersenne primes short of where we actually are. Possibly 4 primes. I've been lobbying a bit for a dual-processor optimized version for Intel. I have little technical basis on which to judge the potential gains, but speculate that memory bus contention and caching efficiency would be improved if both processors were working on the same large exponent. Well before learning of GIMPS and George's program in 1996, I had coded a program to do limited trial division followed by a Lucas-Lehmer test. Having done that, and then seeing the efficiency of George's program, gave me a better appreciation for how much work and skill went into prime95. It's highly optimized, using the counters built into the cpus for the purpose, and using virtually everything known about properties of potential factors and the best algorithms to speed things up both in the factoring attempts and the Lucas Lehmer test. Our best hopes for future speed improvements are 1) the steady march to faster computers in greater numbers ( more multi-cpu systems running multiple instances of the program 1 per cpu) 2) possible future discoveries of better algorithms by mathematicians. Last I heard, there was still some space between the upper and lower bounds to the limit on number of operations required to perform a long multiplication or squaring. 3) modest increments due to optimizations to specific architectures, additional factoring methods, implementation of additional FFT runlengths etc. The easy large gains were implemented long ago, and medium difficulty moderate gains also, leaving diminishing returns requiring significant effort. Nothing built by human hands is perfect, so, sure, the program could be improved! Personally I'd like to see an optimization for Athlon; at the expense of having to load different versions for different processor types, I'd like to see seperate "streamlined" versions of the code optimized for different processor types rather than one monolithic program with everything embedded in it; and I'd like to see the client/server security code somehow "opened", to facilitate the integration of non-Intel clients into PrimeNet, but without sacrificing the trust we have that results have really been computed. Let's keep it simple; disk space is cheap (including space for paging out unused code). I think the current situation where the program detects cpu model and reacts accordingly is a good one; you can still take control by editing the ini file if need be. It keeps it simple for both the novice end user wanting to download a program and get going, and for the program developers. If cpu-specific programs were made instead, the number of distinct programs gets large because the combinations of cpu type and OS is large. Prime95 supports or supported something like 11 cpu type codes. Regarding OS, there are at least 6 types (currently maintained at V20): Win95/NT interactive NT service linux statically linked linux freebsd statically linked bsd Setting CPU type in prime95 V20.4.1 and then examining local.ini, CPUType=3 is a Cyrix 6x86 CPUType=4 is a 486 CPUType=5 is a Pentium CPUType=6 is a Pentium Pro CPUType=7 is an AMD K6 CPUType=8 is a Celeron CPUType=9 is a PentiumII CPUType=10 is a PentiumIII CPUType=11 is an AMD Athlon P-4 code adds another type. (Is there another AMD type?) Presumably cputype 386 and below have been retired (yes 386's were supported, in v13.2 or so) Perhaps some GIMPS participants could offer George Scott nonprivileged account access on some other architectures, so they could do the required development. With increasing exponent size (and therefore run time), I'd like to see PrimeNet evolve to track intermediate residues also to be able to coordinate parallel LL testing double-checking, so that runs which are going wrong can be stopped for investigation without having to be run through to the end. In the QA effort, we've seen a few instances already of errors caught midway by doing a manual/email version of this. Brian Beesley had an error detected this way in his run of a double-check of a 10-megadigit exponent. This exponent takes a PII-400 428 days (yes 14 months) to complete, so detecting the one error and restarting early saves about 10.5 PII-400 months. (Thanks to Rick Pali for providing interim residues to make this savings possible.) Another exponent, 20295631 showed similar results; both Paul Victor Novarese's run and mine produced errors while Brian Beesley's run matched Gordon Spence's. I assume that Brian means sending
Re: Mersenne: idea for a new prime95 version, QA, primenet etc
At 14:57 02/03/2001 -0600, Ken Kriesel wrote: snip In the QA effort, we've seen a few instances already of errors caught midway by doing a manual/email version of this. Brian Beesley had an error detected this way in his run of a double-check of a 10-megadigit exponent. This exponent takes a PII-400 428 days (yes 14 months) to complete, so detecting the one error and restarting early saves about 10.5 PII-400 months. snip After hanging around the Anandtech DC forum for awhile, I'm convinced that this completion time "problem" might be GIMPS biggest hurdle to getting more participation. Very few "loonies" like us are willing to wait 14 months for the calculation of one result. Those folks at Anand's are interested in visible changes in daily statistics, something GIMPS doesn't provide when doing LL testing. Kel U. _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: idea for a new prime95 version, QA, primenet etc
At 02:57 PM 2/3/01 -0600, you wrote: With increasing exponent size (and therefore run time), I'd like to see PrimeNet evolve to track intermediate residues also to be able to coordinate parallel LL testing double-checking, so that runs which are going wrong can be stopped for investigation without having to be run through to the end. In the QA effort, we've seen a few instances already of errors caught midway by doing a manual/email version of this. Brian Beesley had an error detected this way in his run of a double-check of a 10-megadigit exponent. This exponent takes a PII-400 428 days (yes 14 months) to complete, so detecting the one error and restarting early saves about 10.5 PII-400 months. I think this is an EXCELLENT idea, but remember that the "s" values (i.e. the intermediate residue/modulus) for such numbers is quite simply enormous. One couldn't (and shouldn't) check the entire intermediate value, but merely the last "x" bits, where "x" is enough to be reasonably certain that a match isn't random chance -- say, the final 1024 bits. PrimeNet would thus also have to carefully assign the exponents to similar machines with similar runtimes and performance, as it would do little good to assign the primary test to an Athlon-800 and the "real-time" double-check to a much slower machine, as the Athlon would quickly outpace the second check. If a discrepancy was found in a real-time double-check, a ternary run on a different machine could determine which (if either) of the two intermediate residuals was correct, and the tests could proceed from there, with both original machines assuming the same correct residue. Also, if this did evolve, I'd suggest that the "double-checker" be given equal credit with the primary machine, for purposes of credit in history books as discoverers, and/or EFF monies. I assume that Brian means sending intermediate 64-bit residues to Primenet for comparison. (The intermediate save files are too big to send with any frequency and would require a lot of storage.) To automate checking via interim residues would require significant longterm storage at primenet, of quadruples containing exponent, iteration, 64-bit residue, and the source of the information (person or machine ID). When two with matching exponent and iteration but different source were available a comparison would be made; if a discrepancy was found, both runs should be halted while a tiebreaker run was made via a different source, to avoid wasting cpu time of one or both original sources. Since the most likely cause of a discrepancy is error in one run not both, a resume capability as well as a discard capability would be needed. I feel exponents halted for a tiebreaker run should not be expired. I'd agree. Machines awaiting a tie-breaker could move on to factoring, or another smaller double-check. I would not want to see such machines begin another 14-month effort, as once the tiebreaker concluded, that work would be suspended while the first test was concluded. Note that there's a point of futility, at which a "tie-breaker" ought to merely be a triple-check, run to conclusion. Let's say on a 14-month co-op effort, 13.6 months into it a discrepancy was found. Both machines ought to finish, and just have it triple-checked, rather than suspending both, awaiting a tiebreaker. While I'm sure someone could solve for the optimum cutoff point where tiebreakers are not useful, my guess would be that it is around 85% of the way to completion. _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: idea for a new prime95 version, QA, primenet etc
At 04:48 PM 2/3/01 -0500, you wrote: After hanging around the Anandtech DC forum for awhile, I'm convinced that this completion time "problem" might be GIMPS biggest hurdle to getting more participation. Very few "loonies" like us are willing to wait 14 months for the calculation of one result. Those folks at Anand's are interested in visible changes in daily statistics, something GIMPS doesn't provide when doing LL testing. Then why is SETI@home so popular, when it shows little in the way of daily statistics, either? _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: idea for a new prime95 version, QA, primenet etc
At 17:04 02/03/2001 -0500, Jeff Woods wrote: At 04:48 PM 2/3/01 -0500, you wrote: After hanging around the Anandtech DC forum for awhile, I'm convinced that this completion time "problem" might be GIMPS biggest hurdle to getting more participation. Very few "loonies" like us are willing to wait 14 months for the calculation of one result. Those folks at Anand's are interested in visible changes in daily statistics, something GIMPS doesn't provide when doing LL testing. Then why is SETI@home so popular, when it shows little in the way of daily statistics, either? My understanding is that it is possible to have a significant change in daily statistics with SETI@home. A fast machine can complete a SETI work unit in 8 to 10 hours, I believe. Additionally, I believe that SETI@home is "sexier" for the general public and has done a much more thorough job of selling itself via the general media. BTW, I do participate in GIMPS (and have since around 1996 or so), so it's not as if I think it's a bad thing. I just think it will be tough to attract significant membership numbers (say two hundred thousand users, just to throw out a number) when an exponent takes 14 months to complete. Kel _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: idea for a new prime95 version
"Brian J. Beesley" wrote: Some people have indicated they'd like a version of the program with a pretty screen-saver interface. Fair enough, provided we can keep the "classic" version without the extra overhead. The screen-saver idea is important for another reason. I asked several coworkers and secretaries to let Prime95 (NTprime, actually) run on their PCs and they agreed, but they were less than happy when I asked them to change the pretty 3-d screen savers for something that lets NTprime have more cpu power. With the selection Microsoft offers right now, that means "Blank Screen" or "Marquee" - neither is extremely exciting to watch. Before long, most of them went back to the old screen savers and NTprime slowed down to a halt. A pretty screen saver that uses very little cpu time would free up a lot of resources for background computing. It doesnt have to come in the Prime95 package (tough a screen saver that displays progress might be nice), just a separate program would do so we can offer something for those pc users that dont really care what the computer is doing as long as it looks nice (theres a lot of them). Probably the easiest improvement to make is to have the documentation translated into some other languages; I have no idea how good I am at translating technical documentation - I never tried before, but if theres demand, I can give it a try for a german version of "Primzahl95" *g* Regards Brian Beesley Ciao, Alex. _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: idea for a new prime95 version, QA, primenet etc
Jeff Woods wrote: At 04:48 PM 2/3/01 -0500, you wrote: After hanging around the Anandtech DC forum for awhile, I'm convinced that this completion time "problem" might be GIMPS biggest hurdle to getting more participation. Very few "loonies" like us are willing to wait 14 months for the calculation of one result. Those folks at Anand's are interested in visible changes in daily statistics, something GIMPS doesn't provide when doing LL testing. Then why is SETI@home so popular, when it shows little in the way of daily statistics, either? I recently invested a few CPU days in SETI. On my P3-600, I was completing a work unit about every 7-8 hours. Most people's primary machines could certainly complete one work unit per day quite easily. I might point out, though, that now that SETI is producing a new client version which does more testing, and requires roughly twice as long to do each work unit, some folks were complaining on their IRC channel about the time needed to finish each work unit. Nathan _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: idea for a new prime95 version
Alexander Kruppa wrote: "Brian J. Beesley" wrote: Some people have indicated they'd like a version of the program with a pretty screen-saver interface. Fair enough, provided we can keep the "classic" version without the extra overhead. The screen-saver idea is important for another reason. I asked several coworkers and secretaries to let Prime95 (NTprime, actually) run on their PCs and they agreed, but they were less than happy when I asked them to change the pretty 3-d screen savers for something that lets NTprime have more cpu power. With the selection Microsoft offers right now, that means "Blank Screen" or "Marquee" - neither is extremely exciting to watch. Before long, most of them went back to the old screen savers and NTprime slowed down to a halt. A pretty screen saver that uses very little cpu time would free up a lot of resources for background computing. It doesnt have to come in the Prime95 package (tough a screen saver that displays progress might be nice), just a separate program would do so we can offer something for those pc users that dont really care what the computer is doing as long as it looks nice (theres a lot of them). I would say that the best option is either a jumping image or something like the game of life, updated very slowly (I'm thinking of the default xlock display here). Generally, things that jump or stay fixed rather than sliding or, worse, warping are most likely the way to go. I believe Prime95 does come with a screen saver, though it's just a blank screen. Personally, I've used the 'blank screen' option myself since getting involved in distributed computing, but I realize that some folks really want a pretty screen saver. Probably the easiest improvement to make is to have the documentation translated into some other languages; I have no idea how good I am at translating technical documentation - I never tried before, but if theres demand, I can give it a try for a german version of "Primzahl95" *g* I guess I could do something in spanish, but there's a lot of demands on my time right now, and frankly I'd want it proofread by someone who was either a native speaker or had had more than just 5 high school courses! Nathan _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: idea for a new prime95 version, QA, primenet etc
Ken Kriesel wrote: At 09:23 AM 2/3/2001 -, "Brian J. Beesley" [EMAIL PROTECTED] wrote: George has announced the development of new FFT code optimised for Pentium 4. The FFT code is the true heart of the program: it's really hard for me to put into words just how much we all owe to George for his unstinting efforts to make the program as efficient as it is. Suffice it to say that, without George's input, we would probably be two or three Mersenne primes short of where we actually are. Possibly 4 primes. That would obviously depend on how fast David Slowinski was progressing at the time. Remember that much of George's contribution was organizing the project itself, though he certainly has put a huge amount of effort into developing the x86 software. I've been lobbying a bit for a dual-processor optimized version for Intel. I have little technical basis on which to judge the potential gains, but speculate that memory bus contention and caching efficiency would be improved if both processors were working on the same large exponent. IIRC, Slowinski usually ran one exponent on each processor, except when verifying a prime. Well before learning of GIMPS and George's program in 1996, I had coded a program to do limited trial division followed by a Lucas-Lehmer test. Having done that, and then seeing the efficiency of George's program, gave me a better appreciation for how much work and skill went into prime95. It's highly optimized, using the counters built into the cpus for the purpose, and using virtually everything known about properties of potential factors and the best algorithms to speed things up both in the factoring attempts and the Lucas Lehmer test. Our best hopes for future speed improvements are 1) the steady march to faster computers in greater numbers ( more multi-cpu systems running multiple instances of the program 1 per cpu) 2) possible future discoveries of better algorithms by mathematicians. Last I heard, there was still some space between the upper and lower bounds to the limit on number of operations required to perform a long multiplication or squaring. 3) modest increments due to optimizations to specific architectures, additional factoring methods, implementation of additional FFT runlengths etc. The easy large gains were implemented long ago, and medium difficulty moderate gains also, leaving diminishing returns requiring significant effort. Obviously, something else we can all do is encourage our friends to run the program. I am a member of a website known as everything2, and have written articles for that site regarding GIMPS. Feedback is welcome. I am aware that my article is now extremely brief, but it's hard to see what more can be said in a non-technical way. http://www.everything2.com/index.pl?node_id=877902 I have also mentioned GIMPS on my homepage, http://www.acsu.buffalo.edu/~nrussell/ Nothing built by human hands is perfect, so, sure, the program could be improved! Personally I'd like to see an optimization for Athlon; at the expense of having to load different versions for different processor types, I'd like to see seperate "streamlined" versions of the code optimized for different processor types rather than one monolithic program with everything embedded in it; and I'd like to see the client/server security code somehow "opened", to facilitate the integration of non-Intel clients into PrimeNet, but without sacrificing the trust we have that results have really been computed. Let's keep it simple; disk space is cheap (including space for paging out unused code). I think the current situation where the program detects cpu model and reacts accordingly is a good one; you can still take control by editing the ini file if need be. It keeps it simple for both the novice end user wanting to download a program and get going, and for the program developers. If cpu-specific programs were made instead, the number of distinct programs gets large because the combinations of cpu type and OS is large. Agreed there! There is nothing wrong with monolithic programs. Compared with, eg, Netscape or even Winamp, Prime95 requires a very small amount of resources. (snip) Perhaps some GIMPS participants could offer George Scott nonprivileged account access on some other architectures, so they could do the required development. Certainly not a bad idea. I think an Amiga client in particular would attract a fair amount of interest, as would a version specially designed for NetBSD or OpenBSD With increasing exponent size (and therefore run time), I'd like to see PrimeNet evolve to track intermediate residues also to be able to coordinate parallel LL testing double-checking, so that runs which are going wrong can be stopped for investigation without having to be run through to the end. In the QA effort, we've seen a few instances already of
Re: Mersenne: idea for a new prime95 version, QA, primenet etc
Jeff Woods wrote: Then why is SETI@home so popular, when it shows little in the way of daily statistics, either? Because Space/Aliens/E.T./Sci-Fi/etc is popular and SETI lets you participate, not just watch NASA/movies/others... That busy colorful SETI screensaver is also pretty neat to watch. Cheers... Russ _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: idea for a new prime95 version
"Alexander Kruppa" wrote: The screen-saver idea is important for another reason. I asked several coworkers and secretaries to let Prime95 (NTprime, actually) run on their PCs and they agreed, but they were less than happy when I asked them to change the pretty 3-d screen savers for something that lets NTprime have more cpu power. With the selection Microsoft offers right now, that means "Blank Screen" or "Marquee" - neither is extremely exciting to watch. Before long, most of them went back to the old screen savers and NTprime slowed down to a halt. "...slowed down to a halt" is no exaggeration. I've seen screensavers slow it down to more than 7 seconds per iteration at 800+ MHz. I have it running on some PCs where the user has the screensaver set to start after 5 minutes then sets the power management so the monitor turns off after 10 or 15 minutes... and what really bothers me is that the screensaver continues to run even with the monitor off. (Is there some way to prevent that which I don't know about?) One idiot even had her settings such that the screensaver didn't start until _after_ the monitor went off. There are so many screensavers available now that one can be found to match any personality, and I have found it impossible to get people to let go of one they really like. So I don't believe Brian's idea will do very much good; but then every little bit helps. Steve Harris [EMAIL PROTECTED] _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Mersenne: idea for a new prime95 version
hi there, the first idea is more an ideological one. the name is obsolet. :) i vote for winprime or prim4win. the next idea is to give the prime crunchers the choice of doin' what they want to do. for myself, i like to do double test. i could clean up the double tests to prove M(6972593) very fast (even faster than a some old pentiums). i have an tbird 800, and so i will get LLOne tests always. i could set another lame proc in the settings, but it isnt really the same. i'd be pleased to see in the next version a dialog where i can choose the test i wanna do. regards, mohk _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: idea for a new prime95 version
Hi there mohk. I've soon been with the project for 2.5 years and there has always been a choice to set if you want primenet to choose a job for you or if you want to do LL, doublechecking or factoring. v19? added the option of 10 million digit LL:s too. You can find the settings under Primenet in the dropdown-menus. Win32Prime would be the correct name to use there since the name reflects what platform it runs on. Regards /Lars (It seems we need a new prime or nice milestone now. The list is virtually dead :( ) the first idea is more an ideological one. the name is obsolet. :) i vote for winprime or prim4win. the next idea is to give the prime crunchers the choice of doin' what they want to do. for myself, i like to do double test. i could clean up the double tests to prove M(6972593) very fast (even faster than a some old pentiums). i have an tbird 800, and so i will get LLOne tests always. i could set another lame proc in the settings, but it isnt really the same. i'd be pleased to see in the next version a dialog where i can choose the test i wanna do. _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: idea for a new prime95 version
Hi, again :) At 06:03 PM 02.02.01, you wrote: Hi there mohk. I've soon been with the project for 2.5 years and there has always been a choice to set if you want primenet to choose a job for you or if you want to do LL, doublechecking or factoring. v19? added the option of 10 million digit LL:s too. You can find the settings under Primenet in the dropdown-menus. Thanks, I found them, now. Win32Prime would be the correct name to use there since the name reflects what platform it runs on. Regards /Lars (It seems we need a new prime or nice milestone now. The list is virtually dead :( ) I thought a voting creates a new discussion, about increcements, odds etc. C'mon ppl, wake up and give a comment about improving the prime95 proggi. Mohk _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
