Mersenne: Crazy thought of the day...
Seeing as how the Sega Dreamcast was officially released here in the U.S. today... and the list has been REALLY quiet (due to school starting?), I looked at the specs... and sure 'nuff, apparently, the Hitachi SH4 can do 2 FPU ops per cycle (single or double precision) and has the good ole SIMD architecture that the PIII and 3DNow chips seem to support, with 128-bit ops, but again, only for 32-bit single precision floating point numbers... so bummer there... but the superscalar FPU is nice... Anyway, since the Dreamcast runs WinCE, a port to it would be pretty easy... the only problem I see is storing intermediate files, since the "memory packs" are only 128k or something right now... I suppose you could store it somewhere on the 'net by using its built-in 56k modem or whatever... Well, back to work... -Later _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Mersenne: Prime95 version 19 - better late than never
Hi all, Sorry for the delay in releasing v19. It is now available for mersenne mailing list members to beta test. If all goes well, it will be officially released to all GIMPSers in a few weeks. You can get the new version at ftp://entropia.com/gimps/p95b.zip To upgrade prime95, stop and exit the current version. Optionally make a backup of the directory containing prime95. Unzip the new version on top of the old version. Start the new prime95. Next time you contact the server, it will broadcast a welcome message to you. Let me know if there are any problems with this new feature. The message will be deleted prior to the final release of v19. This feature gives us an effective way to inform you of new versions and important bugs or news. Save files are upward compatible from previous versions, but not backward compatible. Thus, do not try this beta if you are in a dual-boot environment. The Linux and NT service versions will be available soon. I'd like to thank the excellent work of the QA team. They located many bugs, bringing you a higher quality beta. The QA team included Ken Kriesel, Brian Beesley, Tom Cage, Jean-Yves Canart, Bryan Fullerton, Marc Getty, Steinar H. Gunderson, Eric Hahn, Alex Healy, Paul Landon, Greg McIntyre, Lawrence Murray, Paul Victor Novarese, Ethan M. O'Connor, Rick Pali, Shane Sanford, Brian Schroeder, Gordon Spence, Joth Tupper, Guillermo Ballester Valor, David Willmore, and Lucas Wiman. And, of course, thanks to Scott Kurowski for his v19 enhancements to the Primenet server. Here is the relevant excerpt from whatsnew.txt: 1) Faster - in some cases as much as 10% faster!. The FFTs were recoded for improved memory and TLB efficiency. Furthermore, optimizations specific to the Pentium Pro and later processors were added. 2) New FFT lengths. The program can now test exponents as large as 79.3 million. Also, smaller FFT lengths are supported for use in ECM and P-1 factoring. 3) More conservative FFT breakpoints. This could actually result in some exponents being slower to test in this version. However, the chance of a fatal rounding error has been reduced. 4) P-1 factoring has been added. Although it is not very practical for large exponents because of a slow GCD routine, it can be used to find new factors of exponents below a few million or so. 5) ECM can now run on large exponents. Once again, the slow GCD routine and high memory requirements might make this impractical for large exponents. 6) ECM and P-1 factoring now support save files. Very handy on lengthy runs. 7) ECM and P-1 factoring lets you specify the amount of memory to use. In some cases, more memory can improve execution speed slightly. 8) A bug in guessing the CPU speed on initial install has been fixed. 9) The preferences dialog now has an option to pause prime95 when a laptop is running on its battery. 10) Error checking has been improved slightly. 11) Factoring is now "layered". That is, prime95 now factors to 2^52, then 2^53, 2^54, and so forth up to the appropriate limit. The factoring output lines have been changed to show percent complete in the current "layer". 12) A bug in running two or more self or torture tests in the same directory has been fixed. 13) Trial factoring above 2^64 is now supported. 14) More trial factoring is now done to take into account the cost of double-checking. 15) Title now contains percent complete when LL testing. By default, the percent complete value is now displayed to 2 decimal places. You can change this by setting PercentPrecision in prime.ini to a value between 0 and 6. 16) Affinity and service name settings moved from prime.ini to local.ini file. Prime95 will automatically move these settings for you. 17) An option to get only 10,000,000 digit numbers to run primality tests on has been added to the Test/Primenet dialog box. See http://www.mersenne.org/prize.htm for rules on claiming the EFF award for finding a 10,000,000 digit prime. 18) The Advanced/Clear primes menu choice has been deleted. 19) The prime95 icon turns yellow when the program is idle. After an error such as ILLEGAL SUMOUT, the icon will blink for 10 seconds. 20) The User Information dialog box allows you to request newsletters and form a team user ID where the team members cannot alter the team name. 21) A bug in the reporting of error counts in the results.txt file has been fixed. 22) The server can now broadcast important messages to the prime95 client. Prime95 will blink the icon until prime95 is activated and then it will display the message. Finally, here is the timings table from my PII-400: V18 timing V19 timing old P-90 timings -- -- 80K 0.038 0.036 96K 0.047 0.0445 0.272 112K0.058 0.0548 0.332 128K0.0645
Mersenne: Factors of DecMega
Scott/all, I downloaded the newest beta for Prime95V19, and set it to ask for 10,000,000 digit Mersennes. In my worktodo.ini file, I got the line: Test=33219379,32 This surprised me! I had tested this number to 2^47, and Alex Kruppa had tested it to at least 2^55 (further investigation revealed 2^60). You should update primenet's files pertaining to this off of those at http://www.informatik.tu-muenchen.de/~kruppa/M33M/index.html -Lucas Wiman _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Mersenne: Re: Factoring in version 19
Hi, At 09:43 PM 9/9/99 -0400, Matthew Smith wrote: I love the new beta. It's much faster and accomodates my PIII. But why is it factoring my most recently assigned number, and not the one I was working on before I upgraded? That's normal. The new version does more factoring than the old version. It is factoring the second number so that if it does have a factor it can get you a new exponent to test and keep your "days of work queued up" greater than 10. Regards, George _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Mersenne: Test/Status in version 19
Hi all, One more thing. The timings in prime95 have been recalibrated to my PII-400 instead of my old, deceased P-90. What does that mean? The short explanation is that you should not believe the estimates given in Test/Status. Over time these estimates will become accurate again. Why is this? When version 18 estimated my PII-400's speed it underestimated by 40%. Over time, the RollingAverage value in local.ini grew to 1400 to compensate for the poor guess and give accurate estimates in Test/Status. Well in version 19, prime95 accurately guesses my PII-400's speed and applying the rolling average of 1400 makes it bring in the expected completion dates by 40%. It won't take too long for the rolling average to come down to close to 1000 -- or you can edit your local.ini file my hand and set the RollingAverage to 1000. I hope that wasn't too confusing... Regards, George _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Mersenne Digest V1 #623
Mersenne Digest Thursday, September 9 1999 Volume 01 : Number 623 -- Date: Tue, 7 Sep 1999 17:01:48 -0400 (EDT) From: Lucas Wiman [EMAIL PROTECTED] Subject: Re: Mersenne: Macintosh Speeds Now my question to the list is, would I be better off having these machines participate in GIMPS via MacGIMPS on MacOS or should I run mprime on Linux? My main concern is performance. Which performs better on the same hardware, MacGIMPS or mprime? I would guesstimate that they all have ~32 MB of RAM, and those that do not can get upgraded to 32 MB easily. Which route should I take? Umm, unless Mac's have changed a lot (ie become intel-based machines), you can't run Mprime under linux. Mprime is written in intel assembler! - -Lucas _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers -- Date: Tue, 7 Sep 1999 17:28:03 -0400 From: "Louis Towles" [EMAIL PROTECTED] Subject: Re: Mersenne: Macintosh Speeds Don't give up on those 24,000 PII hours yet - they can factor, it only floating point math that messes with the video (ati rage pro I think?) Louis Towles - - Original Message - From: Marc Getty [EMAIL PROTECTED] To: Mersenne List [EMAIL PROTECTED] Sent: Tuesday, September 07, 1999 2:39 PM Subject: Mersenne: Macintosh Speeds Okay, so I am here at my new job, got permission to install a GIMPS client on a bunch of machines, cool. It turns out that 50% of the machines that I can install a GIMPS client on are a specific model of Dell that when Prime95 is running causes the video to flicker REALLY bad. So there goes about 24,000 PII MHz down the drain because of poor design by Dell. So in my quest to add more machines to GIMPS I run across 20+ Macs that are in perfectly working order in a storage room. They have been obsolteted simply because they are Macs, and are all mid range Power Macs to low end G3s. The room with plenty of power and plenty of network drops. Perfect dedicated GIMPS clients in my opinion! Now my question to the list is, would I be better off having these machines participate in GIMPS via MacGIMPS on MacOS or should I run mprime on Linux? My main concern is performance. Which performs better on the same hardware, MacGIMPS or mprime? I would guesstimate that they all have ~32 MB of RAM, and those that do not can get upgraded to 32 MB easily. Which route should I take? Thanks in advance for any help! -Marc Marc Getty [EMAIL PROTECTED] Department of Dental Informatics, Temple University http://www.temple.edu/dentistry/di/215-707-8192 _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers -- Date: Wed, 08 Sep 1999 01:16:29 +0300 From: Jukka Santala [EMAIL PROTECTED] Subject: Re: Mersenne: Macintosh Speeds Louis Towles wrote: Don't give up on those 24,000 PII hours yet - they can factor, it only floating point math that messes with the video (ati rage pro I think?) This reminds me, could it be possible to press more CPU-power from existing equipment by utilizing different parts of the processor at the same time... eg. having the FPU work on LL-tests while the integer-side tries trial factoring is a good example. Would the cache losses far outweight any advantage, are the LL-tests for example using also all of the integer-side or would it be a surefire way to lead your CPU into quick heat-death..? Also, while a simple test could be run by multitasking I doubt most schedulers could take this into account, nor do I in fact know if any computers can operate one or both pipelines while doing FPU calc. -Donwulff _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers -- Date: Tue, 07 Sep 1999 20:49:43 -0400 From: Marc Getty [EMAIL PROTECTED] Subject: Mersenne: Macintosh Speeds Louis Towles wrote: Don't give up on those 24,000 PII hours yet - they can factor, it only floating point math that messes with the video (ati rage pro I think?) You are indeed correct, the integrated ATI Rage Pro is the card in the Dell OptiPlexes that I have. When running LL tests the video flickers quite badly. George beat you by 4 minutes by suggesting that I try them as factoring clients, which I will test and see if they too cause screen flicker tomorrow. If they do
