Another reason for high attrition... - Page 3

ET_ · 2004-03-13, 17:32

I would add that many people are actually attracted by statistical challenge: many users tend to team up to reach the "top of the hill".

Il Cunningham Project, or SevennteenOrBust had the chance of teaming groups, maybe they would attract more users. I don't know if they have, because I didn't dip into them lately, but Bob's last message made me think I have an old PII 500 swearing under the load of a double check...

Luigi

dsouza123 · 2004-03-13, 19:05

There are other options to contribute to primenet using Prime95.

Trial factoring or P-1 factoring.

Both are much quicker than LL/DC and if either find a factor
it will save the weeks or months that would have been spent
doing a LL/DC. LL = Lucas-Lehmer test, DC = double checked LL

A 500 Mhz Pentium 3 will do a current size trial factoring in 8 days (24/7),
and P-1 factoring in 12 days.

Trial factoring is fully supported in Prime95 and has its own work type
just requiring switching the work type from 10M or primality or double check
to Request mersenne numbers to factor.
Credit for trial factoring is given, stats are maintained.
Each trial factor gives about 1/10 of a year in factoring credit.

P-1 factoring isn't automated it requires manually entering the assignment.
It normally is done as a pretest before LL. It gives very little factoring credit.
A P-1 factoring test gives 1/100 of a year in factoring credit.

Reboot It · 2004-03-15, 14:29

Quote:

Originally Posted by dsouza123

A P-1 factoring test gives 1/100 of a year in factoring credit.

It's even less than that! I think actually you only get 1/1000 (i.e. 0.001) P90 CPU years for a completed P-1 test.

lycorn · 2004-03-15, 14:47

People with really slow machines can also contribute to GIMPS by joining LMH. Every bit of work is useful, and computers like PIIIs or Athlons (TB and later) do a pretty good job at Trial Factoring.

dsouza123 · 2004-03-15, 15:48

Yes Thanks for the correction.
P-1 is .001 years credit which is 1/1000 not 1/100 of a year.

QuintLeo · 2004-03-17, 13:50

Factoring is also practical on MUCH older machines - a lot of my "farm" runs AMD K5 series CPUs (comparable to the original Pentium), which are completely impractical for LL work (motherboards support 16 Megs of RAM commonly, and upgrading them to their theoretical 64-meg max isn't worth the $$$ or the hassle of finding the needed 16-meg SIMM modules at this late date).

They're QUITE practical for Trial Factoring work, though, abet it might take a month or two per TF run per machine - but that still adds up.

As far as the prize for the 10,000,000 digit prime goes - I don't see that being a primary motivation for MOST folks in GIMPS - there's a few of us that are going for it (I personally don't do LL work on anything else), but I suspect "bragging rights" for those just trying to find a Mersenne Prime at all is a bigger motivation - though there's $5000 for the finder of M41, and in theory M42 as well, if those are below the 10,000,000 digit mark and found before the first 10,000,000 digit prime.

ref. http://www.mersenne.org/prize.htm

For me, though, the money is important but the bragging rights of being one of the higher-ranked contributors is at least as big a factor - elsewise I wouldn't be bouncing around the edge of the Top 100 on trial factoring work....

8-)

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2004-03-13, 17:32	#23
ET_ Banned "Luigi" Aug 2002 Team Italia 11401₈ Posts	I would add that many people are actually attracted by statistical challenge: many users tend to team up to reach the "top of the hill". Il Cunningham Project, or SevennteenOrBust had the chance of teaming groups, maybe they would attract more users. I don't know if they have, because I didn't dip into them lately, but Bob's last message made me think I have an old PII 500 swearing under the load of a double check... Luigi

2004-03-13, 19:05	#24
dsouza123 Sep 2002 2×331 Posts	There are other options to contribute to primenet using Prime95. Trial factoring or P-1 factoring. Both are much quicker than LL/DC and if either find a factor it will save the weeks or months that would have been spent doing a LL/DC. LL = Lucas-Lehmer test, DC = double checked LL A 500 Mhz Pentium 3 will do a current size trial factoring in 8 days (24/7), and P-1 factoring in 12 days. Trial factoring is fully supported in Prime95 and has its own work type just requiring switching the work type from 10M or primality or double check to Request mersenne numbers to factor. Credit for trial factoring is given, stats are maintained. Each trial factor gives about 1/10 of a year in factoring credit. P-1 factoring isn't automated it requires manually entering the assignment. It normally is done as a pretest before LL. It gives very little factoring credit. A P-1 factoring test gives 1/100 of a year in factoring credit.

2004-03-15, 14:47	#26
lycorn "GIMFS" Sep 2002 Oeiras, Portugal 11000101110₂ Posts	People with really slow machines can also contribute to GIMPS by joining LMH. Every bit of work is useful, and computers like PIIIs or Athlons (TB and later) do a pretty good job at Trial Factoring.

2004-03-15, 15:48	#27
dsouza123 Sep 2002 2×331 Posts	Yes Thanks for the correction. P-1 is .001 years credit which is 1/1000 not 1/100 of a year.

2004-03-17, 13:50	#28
QuintLeo Oct 2002 Lost in the hills of Iowa 2⁶·7 Posts	Factoring is also practical on MUCH older machines - a lot of my "farm" runs AMD K5 series CPUs (comparable to the original Pentium), which are completely impractical for LL work (motherboards support 16 Megs of RAM commonly, and upgrading them to their theoretical 64-meg max isn't worth the $$$ or the hassle of finding the needed 16-meg SIMM modules at this late date). They're QUITE practical for Trial Factoring work, though, abet it might take a month or two per TF run per machine - but that still adds up. As far as the prize for the 10,000,000 digit prime goes - I don't see that being a primary motivation for MOST folks in GIMPS - there's a few of us that are going for it (I personally don't do LL work on anything else), but I suspect "bragging rights" for those just trying to find a Mersenne Prime at all is a bigger motivation - though there's $5000 for the finder of M41, and in theory M42 as well, if those are below the 10,000,000 digit mark and found before the first 10,000,000 digit prime. ref. http://www.mersenne.org/prize.htm For me, though, the money is important but the bragging rights of being one of the higher-ranked contributors is at least as big a factor - elsewise I wouldn't be bouncing around the edge of the Top 100 on trial factoring work.... 8-)