Welcome to the Ides of March Challenge

PrimeGrid's Challenge series continues with the "Ides of March Challenge". While this is an LLR Challenge, it's really a tribute to the sievers. As with Caesar's demise, it wasn't the glorious outward appearance that mattered. It was the "behind the scenes" activities that ruled the day.

Now, we don't want to suggest that the sievers are deceptively mischievous. On the contrary, it takes a certain "good for the many" mentality to sieve and forgo the glory of prime finding. Without the sievers, prime finding would be an EXTREMELY time consuming task. :) But let's not put the sievers on too high of a pedestal...cause we know they'll do anything for cobblestones. :D Oh, the glory of 64 bit sieving!

The PPS Sieve is by far the most extensive sieve to date at PrimeGrid. The depth at which 4<k<1200 for n<5M is sieved is truly amazing. What better way to pay homage to the sievers than to go out and find as many primes as we can from their sieve file!

A 24 hour Challenge is being offered on PrimeGrid's Proth Prime Search (LLR) application.

To participate in the Challenge, please select only the Proth Prime Search (LLR) project in your PrimeGrid preferences section. The challenge will begin 15 March 2009 18:00 UTC and end 16 March 2009 18:00 UTC. Application builds are available for Linux 32 bit and Windows 32 bit. These applications will be sent to 64 bit clients. As with all LLR application projects, there is no advantage of 64 bit over 32 bit.

ATTENTION: The primality program LLR is CPU intensive; so, it is vital to have a stable system with good cooling. It does not tolerate "even the slightest of errors." Please see this post for more details on how you can "stress test" your computer. WU's will take ~5 minutes on fast/newer computers and 15+ minutes on slower/older computers. If your computer is highly overclocked, please consider "stress testing" it. Sieving is an excellent alternative for computers that are not able to LLR. :)

Please, please, please make sure your machines are up to the task.

Time zone converter:

The World Clock - Time Zone Converter

NOTE: The countdown clock on the front page uses the host computer time. Therefore, if your computer time is off, so will the countdown clock. For precise timing, use the UTC Time in the data section to the left of the countdown clock.

Scoring Information

Scores will be kept for individuals and teams. Only work units issued AFTER 15 March 2009 18:00 UTC and received BEFORE 16 March 2009 18:00 UTC will be considered for credit. We will use the "prime score" method which is based on the n value (k*b^n-1) to score the challenge. The only difference is that the primary and double checker of a WU will receive the same score.

Therefore, each completed WU will earn a unique score based on its n value. The higher the n, the higher the score. This is different than BOINC cobblestones! A quorum of 2 is NOT needed to award Challenge score - i.e. no double checker. Therefore, each returned result will earn a Challenge score. Please note that if the result is eventually declared invalid, the score will be removed.

For details on how the score is calculated, please see this thread.

At the Conclusion of the Challenge

We kindly ask users "moving on" to ABORT their WU's instead of DETACHING, RESETTING, or PAUSING.

ABORTING WU's allows them to be recycled immediately; thus a much faster "clean up" to the end of an LLR Challenge. DETACHING, RESETTING, and PAUSING WU's causes them to remain in limbo until they EXPIRE. Therefore, we must wait until WU's expire to send them out to be completed.

Please consider either completing what's in the queue or ABORTING them. Thank you. :)

About the Proth Prime Search

The Proth Prime Search is done in collaboration with the Proth Search project. This search looks for primes in the form of k*2^n+1. With the condition 2^n > k, these are often called Proth primes. This project also has the added bonus of possibly finding factors of "classical" Fermat numbers or Generalized Fermat numbers. As this requires PrimeFormGW (PFGW) (a primality-testing program), once PrimeGrid finds a prime, it is then tested on PrimeGrid's servers for divisibility.

Our initial goal was to double check all previous work up to n=500K for odd k<1200 and to fill in any gaps that were missed. We have accomplished that now and have increased it to n=800K. PG LLRNet searched up to n=200,000 and found several missed primes in previously searched ranges. Although primes that small did not make it into the Top 5000 Primes database, the work was still important as it may have led to new factors for "classical" Fermat numbers or Generalized Fermat numbers. While there are many GFN factors, currently there are only about 275 "classical" Fermat number factors known. Current primes found in PPS definitely make it into the Top 5000 Primes database.

Once the 800K goal is reached, we may head to 1M before turning our focus to smaller k values and higher n values. For example, k<300 complete to n=2M, k<600 complete to n=1.5M and so on.

Additional Proth prime testing can be found in PrimeGrid's PRPNet's Proth Prime Search Extended (PPSE) project. This project extends the search range to 1200<k<10000 for n<2M. Current ports available are:

server=0:PPSE:pgllr.mine.nu:7171 1200<k<10000 for n>380K
server=100:PPSE_3:pgllr.mine.nu:9191 1200<k<10000 for n>380K
server=0:PPSE_4:pgllr.mine.nu:10000 1200<k<10000 for 50K<n<360K

For more information about "Proth" primes, please visit these links:

• Proth Prime - The Prime Glossary
  
• Proth Prime - Wolfram MathWorld
  
• Proth Number - Wikipedia

About Proth Search

The Proth Search project was established in 1998 by Ray Ballinger and Wilfrid Keller to coordinate a distributed effort to find Proth primes (primes of the form k*2^n+1) for k < 300. Ray was interested in finding primes while Wilfrid was interested in finding divisors of Fermat number. Since that time it has expanded to include k < 1200. Mark Rodenkirch (aka rogue) has been helping Ray keep the website up to date for the past few years.

Early in 2008, PrimeGrid and Proth Search teamed up to provide a software managed distributed effort to the search. Although it might appear that PrimeGrid is duplicating some of the Proth Search effort by re-doing some ranges, few ranges on Proth Search were ever double-checked. This has resulted in PrimeGrid finding primes that were missed by previous searchers. By the end of 2008, all new primes found by PrimeGrid will be eligible for inclusion in Chris Caldwell's Prime Pages Top 5000. Sometime in 2009, it is expected that over 90% of the tests handed out by PrimeGrids will be numbers that have never been tested.

PrimeGrid intends to continue the search for indefinitely for Proth primes.

What is LLR?

The Lucas-Lehmer-Riesel (LLR) test is a primality test for numbers of the form N = k*2^n − 1, with 2^n > k. Also, LLR is a program developed by Jean Penné that can run the LLR-tests. It includes the Proth test to perform +1 tests and PRP to test non base 2 numbers. See also:

• Lucas-Lehmer-Riesel test (WIKI)
  
• Download LLR by Jean Penné
  

(Edouard Lucas: 1842-1891, Derrick H. Lehmer: 1905-1991, Hans Riesel: born 1929).
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As we move toward the Ides of March challenge interest in PPS LLR would seem to be on the increase.

While it took quite a while for a number of us crunchers to work through the previously checked ranges (500K < n < 540K) but now most primes are 5K reportable we have gone from 540K to 570K in a few weeks-- these primes are entering the 5K list at around 1460 at the moment so they will around for a long time--

I run a small database listing PPS LLR primes & finders and I have seen an increase in new participants over the past few weeks-- Welcome to all & good luck!!!

While PG offers many challenges (official & un-official) there is another constant challenge at the moment--- and that is to hold your position in the top 50 "Top Prime Finders" list--- I am 46th at the time of this post but this can change quickly as new primes are discovered---

I look forward to the coming challenge and good luck to all PG parcipitants.

DoES
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Member of AtP

Shown here is an Australian native rat (Ratus Kickarsus)

This is a friendly reminder.

The countdown clock on the front page uses the host computer time. Therefore, if your computer time is off, so will the countdown clock. For precise timing, use the UTC Time in the data section to the left of the countdown clock.

Best of Luck!
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I prepared myself and sent word out to my team members.
Let us see tomorrow evening what the turnout would be.
I am also curious how many WUs would be crunched and therefore how many primes would materializ out of these completed WUs.
But now let us crunch!

EDIT: Just found a prime *lol* if today would be february...
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Lets get ready to rumble ...

I wish all crunshers a fair challenge. May the fittest win!
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Sysadm@Nbg
my current lucky number: 113856050^65536 + 1
PSA-PRPNet-Stats-URL: http://u-g-f.de/PRPNet/

Just over 1 1/2 hours remain!

Now's the time to start thinking about the finish. This is a friendly reminder to update your clients early, and update often. This prevents overloading the server in the last few seconds of the Challenge and ensures that all of your completed WU's get reported back.

Additionally, if you are "moving on" immediately after the conclusion, please consider lowering your cache or setting your clients to no new work if you already have enough to last to the finish. Afterwards, please consider COMPLETING your cache or ABORTING the WU's. See below for more details.

At the Conclusion of the Challenge

We kindly ask users "moving on" to ABORT their WU's instead of DETACHING, RESETTING, or PAUSING.

ABORTING WU's allows them to be recycled immediately; thus a much faster "clean up" to the end of an LLR Challenge. DETACHING, RESETTING, and PAUSING WU's causes them to remain in limbo until they EXPIRE. Therefore, we must wait until WU's expire to send them out to be completed.

Please consider either completing what's in the queue or ABORTING them. Thank you. :)

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Thank you all for this challenge. It was a big fun! :)

Congrats to team BOINCstats, and special thanks for another tight race to the top position in the team ranking. It's not as close as in december, but 14k challenge points are less than 2500 WUs, so two overclocked quads would have changed the ranking. ;)

Looking forward to see you all again for the Showers to Flowers! 8)
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Yep. Good fun. Thanks for organising. Without Muffy to whip the rat girls in the rodent wheels didn't turn all the time for me* and I had a significant time with computers not running. Aggie The Pew muttered something about lunch and sauntered off and Maddy Rat just curled up and went to sleep but a reportable prime for me nonetheless which was good.

Cheers!

T

* Actually a rat is pretty unlikely to run in a wheel. Maybe because they know they aren't getting anywhere and maybe because if they are called Agg they are fat, greedy slobs.

Yep. Good fun. Thanks for organising. Without Muffy to whip the rat girls in the rodent wheels didn't turn all the time for me* and I had a significant time with computers not running. Aggie The Pew muttered something about lunch and sauntered off and Maddy Rat just curled up and went to sleep but a reportable prime for me nonetheless which was good.

Cheers!

T

* Actually a rat is pretty unlikely to run in a wheel. Maybe because they know they aren't getting anywhere and maybe because if they are called Agg they are fat, greedy slobs.

Thanks DoES. I have been really lucky so far this month with 5 reportable primes so far. Do you know how many were found in the challenge?

I reckon you should order in some moths for your geckos to keep them around.

Cheers!

T

Thanks DoES. I have been really lucky so far this month with 5 reportable primes so far. Do you know how many were found in the challenge?

I reckon you should order in some moths for your geckos to keep them around.

Cheers!

T

Do you know how many were found in the challenge?

Many thanks Pete. I expect we'll get the official figures soon but a really useful link.

Cheese!

T

I'd almost suggest that challenge points are forfeited for such behaviour, but I suspect that would actually be counter-productive. I'm not really sure what the right approach to fix this should be, not least because there *could* be legitimate causes for such events, e.g. power cuts, machine failures, that shouldn't be penalised, nor would I wish to stop the additional involvement that the challenges generate for the project. But it does cause delays to the results, extra load on the server, and guarantees many of us a few days of being the wingman, which could all be avoided by either finishing your queue or managing your cache more sensibly. C'est la vie! :-(
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not that soon because several hosts (with hundreds of WUs in their queues) were simply detached or switched off.

like 97643, 89517 and 97640.

VERY clever move..

i suggest setting the time frame to 6 hours for the next race with short WUs.

i suggest setting the time frame to 6 hours for the next race with short WUs.

FrankHagen wrote:

i suggest setting the time frame to 6 hours for the next race with short WUs.

This will be a good adjustment for the next Challenge.

If the clean-up is really that big of an issue, then reducing the maximum allowable cache during challenges might be a better fix.

Now we'll explore adjusting max cache through out the Challenge and bringing it back down as the end nears.

The Ides of March Challenge is final!!!

Looks like there are new sheriffs in town for 2009 and they go by the name of BOINCstats. They ended last year with a close victory in the Winter Solstice Challenge and have won two straight this year. Congratulations! However, we suspect a few other teams who are wanting to end this streak. Therefore, the next Challenge will be one to watch.

On the individual side, a BIG surprise. Although a member since 2005, he's remained idle since 2006. Relatively new comer, j2satx, takes the victory in a very exciting battle with [SG]marodeur6. Throughout the entire Challenge they were neck and neck.

It was great seeing all the familiar teams and participants as well as all the new ones in the mix. It should make for an interesting rest of the year.

As far as the primes go, they have finally succumbed to the reality of their new residence in the Top 5000 list. The other primes are quite happy that the Challenge is over as this buys them some more time to remain in the unknown. However, we'll keep searching for them.

The sievers did an outstanding job pushing the primes into the primality tester's nets. Over 40 primes were returned to the server during the 24 hours of the Challenge. However, some of those were double checks of primes found in the days before. In the 24 hours after the Challenge another 20 primes were returned. In total that's over 60 primes...almost two weeks worth of primes at our normal rate. :)

Notable primes found:

459*2^593309+1 Divides xGF(593307,3,2)
1087*2^591382+1 Divides xGF(591381,12,5)
351*2^588325+1 Divides GF(588323,6)
195*2^585988+1 Divides GF(585985,12) (double check)
151*2^585044+1 Divides F585042 (double check)
99*2^580738+1 Divides GF(580737,7) (double check)

Overall, this was an OUTSTANDING Challenge. 148 teams and 901 participants joined the Challenge. Over 640K tasks were handed out with about 550K being completed...the other 90K were returned and completed during the "cleanup". We increased in n from about 581K to 597K. Our initial expectations were in the 590K-595K range so the Challenge exceeded that. The server handled everything in stride. We hope this is a sign of good times to come.

Next up (6 weeks from now) is the 30 April - 01 May 48 hour "Showers to Flowers" Challenge on the Prime Sierpinski Problem Sieve. So start tuning up those 64 bit work horses. See ya there!


The top 10 finishers in each category are below: