Mersenne Digest Sunday, 28 February 1999 Volume 01 : Number 515 ---------------------------------------------------------------------- From: Spike Jones <[EMAIL PROTECTED]> Date: Fri, 26 Feb 1999 19:35:21 -0800 Subject: Re: Mersenne: Chronons (was so many primes, so little time) > Aaron Blosser wrote: ... going back to my idea of some > other prize we could offer besides the one for finding the next Mersenne > Prime...anyone come up with anything? How about sweetening the pot for anyone who is doing double checking that discovers a mistake in the first LL analysis? How does this work? The first LL test returns a residual, then the double checking routine takes that residual and... what? How often is a result overturned by double checking? spike ________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm ------------------------------ From: "Aaron Blosser" <[EMAIL PROTECTED]> Date: Fri, 26 Feb 1999 20:41:16 -0700 Subject: RE: Mersenne: Pentium III > But some new instructions of the PIII can probably improve a > little bit the > programs: the prefetch instructions. We can control prefetch and > then fetch > data into all cache levels before using them. The bottleneck of memory I/O > can now be controlled easily ... I looked at the instructions too and didn't see anything really useful. But yes, the code could be optimized a bit in it's use of memory, and perhaps gain a small percentage improvement. If I'm not mistaken, doesn't Prime95 already have different routines to take advantage of the processor being run on? I suppose George could get really carried away, like trying to minimize potential cache-hits on cacheless Celeron chips, but that may be a bit much. Does the new AMD chip coming out offer any new instructions that would be of use? And as for the Merced, it's an almost entire redesign of the Pentium line, where the program will now be responsible for optimizing use of pipelined instructions, or speculative execution. But the execution of the instructions themselves are probably about the same. I have heard that FP speeds would go up some though... Prime95 may run slower on a Merced at the same clock speed as a Xeon, at least until it's recompiled. Sigh... At least by the time Merced comes out, the 0.18 fabs will be busy cranking out chips and we can see Merceds running 750MHz, or whatever, to start. I can't reveal my source, but someone at Intel did mention "copper" to me, so perhaps they'll start really moving that way, promising even greater speeds. What Intel needs to do is some redesign of FP speeds to catch up with RISC design. As it is, they've been holding their own by increasing clock speeds to new highs, but that'll only get you so much. ________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm ------------------------------ From: "Aaron Blosser" <[EMAIL PROTECTED]> Date: Fri, 26 Feb 1999 20:44:47 -0700 Subject: Mersenne: Oops I can't recall, but I think I did some bad math :-) I mentioned picking a Mersenne number at random and the odds of it being a Mersenne Prime... Noting that up to the 34th Mersenne Prime there are in the neighbourhood of 100,000 primes, I *should* have said the odds are 34 chances in 10^5. I think I put the prime number there instead. Doh! And that just makes the odds all that much better anyway. :-) ________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm ------------------------------ From: Spike Jones <[EMAIL PROTECTED]> Date: Fri, 26 Feb 1999 21:25:16 -0800 Subject: Mersenne: Re: Mersennes for Martians Earlier I posted the notion that Mersenne primes might be used to impress extraterrestrial civilizations. After thinking it thru, I think we can make a stronger arguement than that: Mersenne primes might be the *best* yardstick to *prove* a certain level of technological achievement, perhaps the most logical yardstick. Consider: Interstellar messages may be in the form of binary messages where the number of bits is the product of two large primes (call them M and N). Any mathematically oriented receiver would place the bits into an MxN array and color in the 0s (or 1s) and get a black and white picture. These pictures cannot be used to *prove* ones level of technology level for they could easily be faked. We could create a picture of a more advanced city that we currently have, for instance, from a model. But, the primes *cannot* be faked. You either have the computational ability to find them or not. We could send out a list of all known primes as a proof of computational prowess, but I would suggest sending only the Mersennes would prove our technology to any possible exocivilizations with far less power wasted sending all known primes. Can anyone think of any way to *prove* the level of sophistication of our current society, better than a list of Mersenne primes? spike ________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm ------------------------------ From: mark snyder <[EMAIL PROTECTED]> Date: Sat, 27 Feb 1999 09:00:20 -0500 Subject: Mersenne: Re: Mersennes for Martians At 9:25 PM -0800 2/26/99, Spike Jones wrote: >Earlier I posted the notion that Mersenne primes might be used to >impress extraterrestrial civilizations. After thinking it thru, I think we >can make a stronger arguement than that: Mersenne primes might >be the *best* yardstick to *prove* a certain level of technological >achievement, perhaps the most logical yardstick. Except that it might have an unintended effect. Suppose we send out a list of Mersenne primes, and the receiving civilization realizes from the list that we do not know the Theorem of Myxlptlk, which, as every young Golurdian knows, gives an explicit formula for all Mersenne primes. So they immediately come over here and harvest our brains, which are tasty only within a certain range of intelligence. mark ________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm ------------------------------ From: Bryan Fullerton <[EMAIL PROTECTED]> Date: Sat, 27 Feb 1999 10:33:20 -0500 Subject: Re: Mersenne: Re: Mersennes for Martians On Fri, Feb 26, 1999 at 09:25:16PM -0800, Spike Jones <[EMAIL PROTECTED]> wrote: > Earlier I posted the notion that Mersenne primes might be used to > impress extraterrestrial civilizations. After thinking it thru, I think we > can make a stronger arguement than that: Mersenne primes might > be the *best* yardstick to *prove* a certain level of technological > achievement, perhaps the most logical yardstick. Of course, that yardstick measures both ways - it could also prove technological inferiority... "They've only found the first 3000 2^n-1 primes? Such slow creatures!" ;) Bryan - -- Bryan Fullerton http://www.samurai.com/ Owner, Lead Consultant http://www.feh.net/ Samurai Consulting http://www.icomm.ca/ "No, we don't do seppuku." Can you feel the Ohmu call? ________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm ------------------------------ From: Spike Jones <[EMAIL PROTECTED]> Date: Sat, 27 Feb 1999 10:45:55 -0800 Subject: Mersenne: Re: Mersennes for Martians > Spike Jones wrote: Mersenne primes might > >be the *best* yardstick to *prove* a certain level of technological > >achievement, perhaps the most logical yardstick. > > mark snyder wrote: Except that it might have an unintended effect. Suppose we > send out a list > of Mersenne primes, and the receiving civilization realizes from the list > that we do not know the Theorem of Myxlptlk, which, as every young > Golurdian knows, gives an explicit formula for all Mersenne primes. So they > immediately come over here and harvest our brains, which are tasty only > within a certain range of intelligence. I admit, this is the chance we take. However, I am betting that interstellar travel is *inherently* difficult, perhaps is not practical, and that there exists no Myxlptlk theorem. But if there is such a theorem, I suuure would like to find it. {8^D I propose we send out our list when we hit 40, which I suspect is in the next decade. spike ________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm ------------------------------ From: Spike Jones <[EMAIL PROTECTED]> Date: Sat, 27 Feb 1999 10:52:04 -0800 Subject: Re: Mersenne: Re: Mersennes for Martians > Spike Jones <[EMAIL PROTECTED]> wrote: Mersenne primes might > > be the *best* yardstick to *prove* a certain level of technological > > achievement, perhaps the most logical yardstick. > > Bryan Fullerton wrote: Of course, that yardstick measures both ways - it could > also prove technological inferiority... "They've only found the first 3000 2^n-1 > primes? > Such slow creatures!" ;) True Bryan, but recall that lithium computer exercise we did last week. All ET intelligences would be subject to the same physical constraints that we are. Unless some ET figures out a Myxlptlk theorum that generates all the 2^n-1 primes, just having found 37 of them will impress advanced societies. Specifically, that we are so processor rich that we can afford to squander it on amusing ourselves. Also, consider the future of our own planet. Future civilizations here will measure our progress by how much time we spent looking for and how many Mersenne primes we knew way back in the 20th century. spike ________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm ------------------------------ From: Simon Burge <[EMAIL PROTECTED]> Date: Sun, 28 Feb 1999 07:34:56 +1100 Subject: Re: Mersenne: Re: Mersennes for Martians Spike Jones wrote: > > Spike Jones <[EMAIL PROTECTED]> wrote: Mersenne primes might > > > be the *best* yardstick to *prove* a certain level of technological > > > achievement, perhaps the most logical yardstick. > > > > Bryan Fullerton wrote: Of course, that yardstick measures both ways - it could > > also prove technological inferiority... "They've only found the first 3000 2^n-1 > > primes? > > Such slow creatures!" ;) > > True Bryan, but recall that lithium computer exercise we did last week. > All ET intelligences would be subject to the same physical constraints > that we are. Unless some ET figures out a Myxlptlk theorum that generates > all the 2^n-1 primes, just having found 37 of them will impress advanced > societies. Specifically, that we are so processor rich that we can afford > to squander it on amusing ourselves. Perhaps we should wait until the supposed close breakthrough of computing with quantum mechanics... Simon. ________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm ------------------------------ From: Henk Stokhorst <[EMAIL PROTECTED]> Date: Sun, 28 Feb 1999 01:13:43 +0100 Subject: Mersenne: Re: Mersennes for Martians Spike Jones wrote: > Specifically, that we are so processor rich that we can afford > to squander it on amusing ourselves. Nope, they will just wonder what they have overlooked that makes Mersenne Primes so basic to a culture. YotN, Henk Stokhorst. PS. I once saw a TV documentary where one astronomer talking about the Seti proposed to broadcast the first one hundred primes from Earth since there is no natural source that can emit them, and they are independant of the numberbase one uses Furthermore primes are easily noticed as interesting numbers. ________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm ------------------------------ From: Paul Derbyshire <[EMAIL PROTECTED]> Date: Sat, 27 Feb 1999 06:02:05 -0500 Subject: Mersenne: Interesting... DoubleCheck=1945637,58 DoubleCheck=1948981,58 DoubleCheck=2334223,58 Test=7062007,62 Interesting. Two more doublechecks after the current one, and then a fresh LL test on an exponent in the 7E6 ballpark. Not that I'm complaining :-) It should come around to that giant exponent right around when the new PII-333 box arrives ;-) - -- .*. "Clouds are not spheres, mountains are not cones, coastlines are not - -() < circles, and bark is not smooth, nor does lightning travel in a `*' straight line." ------------------------------------------------- -- B. Mandelbrot |http://surf.to/pgd.net _____________________ ____|________ Paul Derbyshire [EMAIL PROTECTED] Programmer & Humanist|ICQ: 10423848| ________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm ------------------------------ From: Paul Derbyshire <[EMAIL PROTECTED]> Date: Sun, 28 Feb 1999 00:47:52 -0500 Subject: RE: Mersenne: Pentium III >...minimize possible cache hits on cacheless Celeron chips... Isn't that a vacuous statement? :-) (Say, I never heard of any cacheless Celeron chips, or any other cacheless chip since the late eighties...) - -- .*. "Clouds are not spheres, mountains are not cones, coastlines are not - -() < circles, and bark is not smooth, nor does lightning travel in a `*' straight line." ------------------------------------------------- -- B. Mandelbrot |http://surf.to/pgd.net _____________________ ____|________ Paul Derbyshire [EMAIL PROTECTED] Programmer & Humanist|ICQ: 10423848| ________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm ------------------------------ From: Paul Derbyshire <[EMAIL PROTECTED]> Date: Sun, 28 Feb 1999 00:55:18 -0500 Subject: Re: Mersenne: Chronons (was so many primes, so little time) At 08:17 PM 2/25/99 -0800, you wrote: >As for errors in the original post, no one hammered >me for calling 1E15 a trillion either... 1E15 is a quadrillion dammit! 1E12 is a trillion!!! <g> - -- .*. "Clouds are not spheres, mountains are not cones, coastlines are not - -() < circles, and bark is not smooth, nor does lightning travel in a `*' straight line." ------------------------------------------------- -- B. Mandelbrot |http://surf.to/pgd.net _____________________ ____|________ Paul Derbyshire [EMAIL PROTECTED] Programmer & Humanist|ICQ: 10423848| ________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm ------------------------------ From: Paul Derbyshire <[EMAIL PROTECTED]> Date: Sun, 28 Feb 1999 00:59:12 -0500 Subject: Re: Mersenne: Re: Mersennes for Martians At 09:25 PM 2/26/99 -0800, you wrote: >Can anyone think of any way to *prove* the level of sophistication >of our current society, better than a list of Mersenne primes? spike An image of the Mandelbrot set... <g> - -- .*. "Clouds are not spheres, mountains are not cones, coastlines are not - -() < circles, and bark is not smooth, nor does lightning travel in a `*' straight line." ------------------------------------------------- -- B. Mandelbrot |http://surf.to/pgd.net _____________________ ____|________ Paul Derbyshire [EMAIL PROTECTED] Programmer & Humanist|ICQ: 10423848| ________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm ------------------------------ From: Paul Derbyshire <[EMAIL PROTECTED]> Date: Sun, 28 Feb 1999 03:58:27 -0500 Subject: Mersenne: Fabs. At 11:24 AM 2/26/99 -0700, you wrote: Re: PIII speed: >...don't expect a speed improvement beyond the obvious boost to >500MHz (and faster once .18 fabs come online). Fabs? What are those? I found a fabs in my float.h once, never did see it again. I think it was for finding absolute values. :-) I guess I have to make a guess here. A .18 fab is... * A nasty hypervelocity rifle with small caliber but potent slugs, hopefully in a Quake type game and not being manufactured in a black market weapons factory in the Middle East. * A version of a program. A very very very very beta version. * A very small something-or-other with which you something-or-other your something-or-other in order to achieve something-or-other. Which of these is correct? :-) - -- .*. "Clouds are not spheres, mountains are not cones, coastlines are not - -() < circles, and bark is not smooth, nor does lightning travel in a `*' straight line." ------------------------------------------------- -- B. Mandelbrot |http://surf.to/pgd.net _____________________ ____|________ Paul Derbyshire [EMAIL PROTECTED] Programmer & Humanist|ICQ: 10423848| ________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm ------------------------------ End of Mersenne Digest V1 #515 ******************************
