Re: Mersenne: LL Factoring DE Crediting
On Tue, Jun 29, 1999 at 12:12:28PM +0200 (OK, late reply, it suddenly struck me that I hadn't replied...), Sturle Sunde wrote: number which is tested already, you climb by pushing someone else down. That isn't very likely to happen, is it? Am I the only one who doesn't trial-factor random LL tested exponents? :-) If I don't factor far enough, that will eventualy happen to me. H, perhaps... (Of course, factoring is a good idea in general; it saves you from wasting times on LL tests.) Therefore I think that Georges formula, just counting LL-results for every Mersenne without a factor in the database and give credit to the people who tested those numbers, is a beautiful solution. But what if a person had a load (say any number for the discussion, 1000 might be a bit extreme, but still _possible_) of 486s only, and didn't want them to LL test becuase that takes _ages_? (As we've discussed earlier, some Dells have problems with flickering during LL tests, which I've experienced myself the last two weeks.) (Then again, it saves some problems -- people with P6-class CPUs (that have almost twice as much `factoring speed' as `LL speed' per cycle (in P90 CPU year)) won't be tempted to do factoring only, and run up the ranks :-)) As long as you do get assigned normal, first-time LL tests (double-checks are already trial-factored with only a marginal chance of a factor missed, so you get an unfair advantage -- no factoring has to be done), George's setup is perfect. When things get a bit more complex, IPS is better, IMHO. /* Steinar */ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm
Re: Mersenne: LL Factoring DE Crediting
On Mon, Jun 28, 1999 at 11:03:26PM -0400, David A. Miller wrote: If there is a way for the user to control the amount of factoring, then it is news to me. It's in the `Advanced/Factor' menu choice. mprime hasn't got this option, but I haven't bothered to send in a bug report. /* Steinar */ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm
Mersenne: LL Factoring DE Crediting
The GIMPS home page explains the following "Finally, if a factor is later found for a Mersenne number or the Lucas-Lehmer result is found to be incorrect, then you will "lose credit" for the time spent running the test." It is on www.mersenne.org/top.htm always struck me as odd I must admit. At the time the test was done it obviously WAS required, so why the subsequent penalty when we make advances and can factor much deeper? regards Gordon Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm
Re: Mersenne: LL Factoring DE Crediting
At 09:59 PM 6/28/99 +0100, Gordon Spence wrote: The GIMPS home page explains the following "Finally, if a factor is later found for a Mersenne number or the Lucas-Lehmer result is found to be incorrect, then you will "lose credit" for the time spent running the test." It is on www.mersenne.org/top.htm always struck me as odd I must admit. It isn't very clear, but the purpose may have been to discourage bogus positive results, because they will eventually be double-checked. +--+ | Jud "program first and think later" McCranie | +--+ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm
Re: Mersenne: LL Factoring DE Crediting
Hi all, At 09:59 PM 6/28/99 +0100, Gordon Spence wrote: if a factor is later found for a Mersenne number or the Lucas-Lehmer result is found to be incorrect, then you will "lose credit" for the time spent running the test." It is on www.mersenne.org/top.htm always struck me as odd I must admit. At the time the test was done it obviously WAS required, so why the subsequent penalty when we make advances and can factor much deeper? The explanation is really simple. It saves me from having to keep track of too much data (the bad results and the ones that a factor was later found). However, since the v17 bug, I've had to modify my procedures anyway and give credit for those incorrect results. I suppose it wouldn't be too hard to do the same for factors found and LL results proven incorrect. Regards, George Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm
Re: Mersenne: LL Factoring DE Crediting
Brian J. Beesley writes: thereafter. I think George's idea was to encourage people to do the appropriate amount of trial factoring - if you didn't do enough, and proceed to run the LL test, you lose the credit because you should This doesn't fit with my understanding of how Prime95 works. I though that the program automatically chose the factoring depth using a formula that weighs the chance of finding a factor against the time that would be required for the LL test. If there is a way for the user to control the amount of factoring, then it is news to me. David A. Miller Rumors of my existence have been greatly exaggerated. Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm
