Welcome to the Dog Days of Summer Challenge

PrimeGrid’s Challenge series continues with the Dog Days of Summer Challenge. Most dictionaries define the Dog Days as follows:

1 : the period between early July and early September when the hot sultry weather of summer usually occurs in the northern hemisphere
2 : a period of stagnation or inactivity

Please come join us in ushering an end to the hot sweltering days of summer. A 48 hour Challenge is being offered on PrimeGrid's 321 Prime Search (Sieve) application.

To participate in the Challenge, please select only the 321 Prime Search (Sieve) project in your PrimeGrid preferences section. The Challenge will begin 20 August 2010 18:00 UTC and end 22 August 2010 18:00 UTC. Application builds are available for MacIntel, Linux 32 & 64 bit and Windows 32 & 64 bit. Note: 64 bit builds benefit from a 1.7X speed advantage over 32 bit...so 1.7X the credit. :)

NOTE: In your PrimeGrid preferences section, set "Send work from any subproject if selected projects have no work" to no to guarantee that no other work will be sent.

Recommendation: The 321 (Sieve) application requires a one time download of a 6.7MB sieve file. Please consider running a few 321 (Sieve) WU's before the Challenge begins so your client will already have the sieve file. This way, bandwidth can be used to deliver WU's instead of the sieve file. :) Thank you!

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 20 August 2010 18:00 UTC and received BEFORE 22 August 2010 18:00 UTC will be considered for credit. Since this is a fixed credit project, we'll be using cobblestones for scoring.

About 321 Prime Search

321 Prime Search is a continuation of Paul Underwood's 321 Search (see below) which looked for primes of the form 3*2^n-1. PrimeGrid added the +1 form and continues the search up to n=25M.

Primes known for 3*2^n+1 occur at the following n:

1, 2, 5, 6, 8, 12, 18, 30, 36, 41, 66, 189, 201, 209, 276, 353, 408, 438, 534, 2208, 2816, 3168, 3189, 3912, 20909, 34350, 42294, 42665, 44685, 48150, 54792, 55182, 59973, 80190, 157169, 213321, 303093, 362765, 382449, 709968, 801978, 916773, 1832496, 2145353, 2478785, 5082306

Primes known for 3*2^n-1 occur at the following n:

1, 2, 3, 4, 6, 7, 11, 18, 34, 38, 43, 55, 64, 76, 94, 103, 143, 206, 216, 306, 324, 391, 458, 470, 827, 1274, 3276, 4204, 5134, 7559, 12676, 14898, 18123, 18819, 25690, 26459, 41628, 51387, 71783, 80330, 85687, 88171, 97063, 123630, 155930, 164987, 234760, 414840, 584995, 702038, 727699, 992700, 1201046, 1232255, 2312734, 3136255, 4235414

What is sieving?

Sieving is the first step to prime finding. In general, a sieve separates wanted/desired elements from unwanted material using a tool such as a mesh, net or other filtration or distillation methods. The word "sift" derives from this term. (Wikipedia - Sieve)

In PrimeGrid's case, the desired elements ultimately are prime numbers and the unwanted material are composite numbers. Our tool of choice for PSP/SoB sieve is Geoff Reynolds' sr2sieve program. It eliminates possible candidates by removing numbers that have small factors. As this process is much faster than primality testing, it is good to thoroughly sieve a data set before primality testing.

Sieving removes many candidates at the beginning. However, the deeper the sieve goes, the slower the rate of removal, till eventually sieving removes candidates at the same rate as primality testing. This is sometimes referred to as "optimal depth". Primality testing is recommended at this point.

There are many factors that determine how much time and how deep to sieve. After sieving, all the remaining candidates must be primality tested to determine their "prime" status.

About 321 Search

321 Search began in February 2003 from a post by Paul Underwood seeking help from interested parties in a prime search attempt of the form 3*2^n-1. The initial goal was to build upon the completed work at Proth Search and extend the list of known primes to an exponent of 1 million (n=1M). That was quickly achieved so they advanced their goal to finding a mega prime for which they sieved up to n=5M.

As seen on PrimeGrid's front page, that goal was achieved on 23 Mar 2008, 7:57:28 UTC, when Dylan Bennett of Canada returned a positive result for n=4235414 (3*2^4235414-1). official announcement | decimal representation

32 bit OS with 64 bit CPU

This is for those who are "driving with the hand brake active" (running a 32 bit OS on a 64 bit machine) ;) Wubi is a very nice tool that installs Ubuntu as a dual boot to your 64 bit machine. It's as simple as adding a program to Windows. You can even uninstall it like you would any other program. :)

Wubi - Ubuntu Installer

After getting 64 bit OS running on your machine, here's a link to ALL BOINC clients (including Linux x64): http://boinc.berkeley.edu/download_all.php If you are new to Linux and need help getting set up, let us know.

It really is simple. :) With that said, check what installations WUBI will NOT work on: Unsupported set-ups

Ubuntu has a power save feature that throttles the CPU frequency down to save power. It does not treat BOINC as an active program so will throttle down thus causing under-performance. For those downloading the latest Ubuntu 10.04 (http://www.ubuntu.com/), please follow these directions to make sure the frequency is not throttled down while BOINC is running:

1. In Ubuntu, right click the top menu bar
2. Select add to panel
3. Select "CPU Frequency Scaling Monitor"
4. Click add

This will add a processor icon to the top menu. Click on the icon and set to "Performance". This also allows you to see the CPU frequency.
____________

The rat girls have taken offence due to the mention of dogs and say they won't take part*. Good luck and good fun with it.

The latest version of Ubuntu is in fact 10.04 not 9.10 as mentioned in the original post.

Cheers!

T

*Actually I'm on holiday.

I'm greatly looking forward to this challenge, largely because it will give me a good excuse to work on my 321 Sieve badge.
____________

Sorry mouth engaged before brain. Ignore this

Sorry mouth engaged before brain. Ignore this

Don't worry. That is quite normal behaviour for a rat. Cute pic BTW. Reminds me of my Guinna pig called Eric. Sure do miss the little rodent.

How to Join the Challenge

To participate in the Challenge, please select only the 321Prime Search (Sieve) project in your PrimeGrid preferences section. Also, set "Send work from any subproject if selected projects have no work" to no to guarantee that no other work will be sent. The challenge will begin 20 August 2010 18:00 UTC and end 22 August 2010 18:00 UTC.

Application builds are available for the following:

• Microsoft Windows (98 or later) running on an Intel x86-compatible CPU
  
• Microsoft Windows running on an AMD x86_64 or Intel EM64T CPU
  
• Linux running on an Intel x86-compatible CPU
  
• Linux running on an AMD x86_64 or Intel EM64T CPU
  
• Mac OS 10.4 or later running on Intel
  
• Mac OS 10.5+ running on an Intel 64-bit CPU
  

Note: 64 bit builds benefit from a 1.7X speed advantage over 32 bit...so 1.7X the credit. :)

Recommendation: The 321 (Sieve) application requires a one time download of a 6.7MB sieve file. Please consider running a few 321 (Sieve) WU's before the Challenge begins so your client will already have the sieve file. This way, bandwidth can be used to deliver WU's instead of the sieve file. :) Thank you!

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 20 August 2010 18:00 UTC and received BEFORE 22 August 2010 18:00 UTC will be considered for credit. Since this is a fixed credit project, we'll be using cobblestones for scoring.

Stats will be available on the front page next to the clock within 30 minutes after the start.

What to expect at Challenge start

The server always gets hit hard at the beginning of the Challenge. However, we will be using the same procedure that we used last year for all the Challenges which proved very successful. A few hours before the start (20 August 2010 18:00 UTC) "max cache" will be dropped to 16 tasks per core. Additionally, "max to send" will be dropped to 8 tasks per core. Anyone attempting to request more will be met with "max cache" messages.

We'll raise the buffer to at least 50K. At the start of the Challenge, these settings will be adjusted as necessary. Afterwards, as conditions allow, we'll raise "max cache". We'll continue to increase "max cache" when the server can handle it until a full 5 days max cache is possible.

This method allows the greatest opportunity for the most clients to get work. Even if it's just 1 task for the first 5 minutes, at least the client is crunching. Past Challenges have shown that clients have an excellent chance to reach "max cache" before their first task is complete. We expect the same this time.

Strategies for starting the Challenge

Depending on a variety of factors, different strategies work for different users. Here are just a few to consider:

• large farm, user can be present at start
  -Set Computer is connected to the Internet about every to 0 days
  -Set Maintain enough work for an additional to 0 days
  -Change PrimeGrid preferences to a fast WU project such as PPS (LLR)
  -At Challenge start, update PrimeGrid preferences and only select 321 (Sieve) project
  -At worse, you'll only be 1 PPS (LLR) WU late on each core starting the Challenge.
  -After all machines have work, increase Maintain enough work for an additional
  
• large farm, user NOT able to be present at start
  -Same settings as above.
  -At worse, you'll only be 1 WU late on each core starting the Challenge.
  
• a few computers, user can be present at start
  -Change PrimeGrid preferences and only select 321 (Sieve) project
  -Set computers to "No New Tasks" for PrimeGrid
  -At Challenge Start, update computers to "Allow New Tasks"
  
• a few computers, user NOT able to be present at start
  -Set Computer is connected to the Internet about every to 0 days
  -Set Maintain enough work for an additional to 0 days
  -Change PrimeGrid preferences and only select 321 (Sieve) project
  -At worse, you'll only be 1 WU late on each core starting the Challenge.

NOTE: This presumes you have all other BOINC projects suspended.

Best of Luck to everyone!
____________

i am still watching that 50 hour deadline - you do know what will happen if you set max cache to 5 days?

i am still watching that 50 hour deadline - you do know what will happen if you set max cache to 5 days?

Current 321 (Sieve) tasks have a 7 day deadline. I'm not able to see the 50 hour deadline you are referring to.

i'm talking about PPS-Sieve. everyone who has this one active, will probably run only very few challenge WU's then because boinc will decide to pull the shorter ones ahead once they reach the panic-mode limit.

you probably should consider raising the deadline on PPS-sieve.

The same work that we'll be crunching during the challenge is available now. However, please note that only work units issued AFTER 20 August 2010 18:00 UTC and received BEFORE 22 August 2010 18:00 UTC will be considered for credit.
____________

There are several thousant of those results. They are "stuck" and require manual intervention - because of that and not high amounts, their removal is at a low priority. I did remove your WU right now though :)
____________

24 hours to go!!!

When will the end come to this summer heat??? As soon as Sirius is separated from the sun!!! In 24 hours, come join us to help hasten Sirius' departure and thus, bring back cooler days. A 48 hour Challenge is being offered on the 321 Prime Search (Sieve).

Please once again review the "Welcome" post as well as the "How to Join" post so you can be informed and make any last minute adjustments that are necessary.

A few hours before the Challenge, we begin to monitor the Meebo chat room at the bottom of the forum page. If at any time PrimeGrid becomes unresponsive, you can still access the Meebo chat room externally here: http://www.meebo.com/room/primegrid/

Before the start, the Subproject stats on the Server Status page will be disabled as will the 24 hour stats on the bottom of the front page. Also, the Top Primes Finder page will be disabled. This is all done to free up as much resources as possible to allow the server to send and receive work.

Recommendation: The 321 (Sieve) application requires a one time download of a 6.7MB sieve file. Please consider running a few 321 (Sieve) WU's before the Challenge begins so your client will already have the sieve file. This way, bandwidth can be used to deliver WU's instead of the sieve file. :) Thank you!

What to expect at Challenge start

The server always gets hit hard at the beginning of the Challenge. However, we will use the same procedure that we have been for over a year now for all the Challenges which has proved very successful. A few hours before the start (20 August 2010 18:00 UTC) "max cache" will be dropped to 16 tasks per core. Additionally, "max to send" will be dropped to 8 tasks per core. Attempting to request more will be met with "max cache" messages.

We'll raise the buffer to at least 50K. At the start of the Challenge, these settings will be adjusted as necessary. We'll make the first adjustment around 30 minutes post start by raising "max cache" to 32. We'll continue to increase "max cache" when the server can handle it until a full 48 hour max cache is possible.

This method allows the greatest opportunity for the most clients to get work. Even if it's just 1 task for the first 5 minutes, at least the client is crunching. Past Challenges have shown that clients have a good chance to reach "max cache" before their first task is complete. We expect the same this time.

Stats will be available on the front page next to the clock within 30 minutes after the start.

BOINCstats provides hourly updates of Project Challenges. There you can view user and team credit and ranking trends.
____________

The average duration of 1 task is about 3 hours, so the first request could result in sending enough work for the whole challenge.
Why not lower it to max 2 or 4 tasks?

I hear rumor you picked up the latest server side code? I hope that isn't true.... My experiences with it over on AUQA have been really poor. For example they decided to assume there is no difference in performance between 64bit apps and 32bit apps so they randomly send one and if there is a performance difference over "time" the server will start sending out the correct apps. The server side also has implemented the <sarcasm>new improved </sarcasm> credit system ignoring your existing settings and credit choices..... ugg.... I guess we will find out soon......

My first set of WUs is at 12%.
____________

The start was no problem. THX!
____________

My first set of WUs is at 12%.

21% :P

I am surprised, 312 Sieve crunching goes on very slowly for me. Half a year before it took 4,5 hours to crunch a WU (getting me 190 credits), now it takes 6 hours and gets me only 160 credits. Are there something wrong with credit calculation?

I haven't been able to get work for my GPUs since the challenge started:

What's going on here?

Challenge Update

It appears that we experienced a very smooth start this time. Of course, we had longer WU's on our side. :) However, a few other precautions were taken. We are still working on a few issues with some ppsieve builds trashing WU's. For the start, that project was minimized. Additionally, the inflated/erratic bandwidth that we have been experiencing for the past month has finally been resolved. Both of these measures freed up more resources that are conducive to a good start.

Almost 20K tasks have been completed so far...that's about 400T of sieve work. At this rate, we could possibly complete 2P in 48 hours!!! Amazing! :)

Thank to everyone for participating...best of luck!
____________

Way to go Ralf, you must have some quick crunchers, you are among the first four individuals reporting :)

After I switched my GTX back on I've finally managed to break the 100 minute barrier.

21 Aug 2010 4:17:38 UTC 22 Aug 2010 5:33:36 UTC 5,999.37 5,992.90 164.43 321 Prime Search (Sieve) v1.13
21 Aug 2010 4:17:38 UTC 22 Aug 2010 5:33:36 UTC 5,999.34 5,990.13 164.43 321 Prime Search (Sieve) v1.13

I've expected increasing runtimes...
____________

Preparing for the Final!

With about 4 hours remaining, now would be a good time to start preparing for the end of the Challenge. Normally, the server gets hit hard as the Challenge draws to an end with everyone submitting their last results. However, with these long WU's we don't expect too much of a stress. Nevertheless, please remember to upload early and often.

Only work units issued AFTER 20 AUGUST 2010 18:00 UTC and received BEFORE 22 AUGUST 2010 18:00 UTC will be considered for credit.

For those "moving on" at the conclusion of the Challenge, we ask that you abort your WU's after the end. This helps out greatly with loose WU's lying around waiting to expire. However, if you have the resources, please consider completing the work in your cache before "moving on".

Since this is a sieve Challenge, there is not need for a "clean up" period. Therefore, the results will be final shortly after the conclusion (when the validator has processed all the Challenge WU's).

Standings: Participants | Teams

Good Luck to everyone!
____________

27th, that is cool!
My Core Duo Notebook tripped out once due to a faulted fan but could be resurrected.

The results are Final!

The Dog Days are over! Well, at least the Challenge is. For some, cooler days have already returned. The raining down of factors helped cool the air and bring in a nice breeze. For others, Sirius appears to be standing his ground. Similar to the ground hog, 6 more weeks of hot weather. :D Let's hope not!

2.89P of sieve work was crunched in 144K tasks resulting in over 23.7M cobblestones awarded. In terms of cobblestones in a 24 hour period, this Challenge (18.2M - Challenge + regular work) ranks second only to the June 18th Summer Solstice Challenge (19.6M)

The 321 sieve reached an incomplete depth of over 38.4P!!! Roughly 2K factors were found. :) This is the first notice to everyone that 321 sieve is approaching optimal depth for the n<25M range. The search is just passed 6M on the primality side which means we have many years of testing ahead of us. Therefore, the 25M<n<50M range probably will not be started any time soon.

145 teams and 985 individuals participated in the Challenge.

The Challenge Points stats will be updated soon. Congratulations to Team Norway as the top team and shanky123 as the top individual. Remember, the top 100 individual and top 50 team places earn points for this Challenge.

Thank you again to everyone. We appreciate your participation and hope you had fun! Enjoy the remaining days of summer!!! We look forward to seeing you in the fall at the next Challenge - Calendula - 24 September - 13 days on the PSP (LLR) application! This is PrimeGrid's longest Challenge this year and worth the most Challenge points. Who knows, we may even find our first PSP prime. :)

Stats: Participants | Teams

1. Please check out PrimeGrid's Fall 2010 Donation Drive.
   
2. Turan@BOINC has issued a "team" challenge at BOINCstats. We are attempting to reach at least 47 teams participating. If your team is already crunching at PrimeGrid normally, might as well have your team founder sign up at BOINCstats. It's very easy to participate...just crunch at PG during the challenge period. For more information, please see the Team Challenge thread.
   

____________

I had hoped having a couple more cores would get me the top 100. Missed it by 1.

My internet died sometime shortly after I went to bed last night, as such a large amount of my work during the challenge went unreported and I stopped being able to get tasks. Oh well, there is always next time.
____________

Top 10 Individuals
1 shanky123 Team Norway 3510125.08

Shanky123 is a madman ;D (I mean that in a good way.) No vacation/loss of Internet connectivity this time, I'm guessing?

Congrats to Shanky123 & Team Norway from a mid-level SetiUSA cruncher.

16 PoorBoy 343.75 237.00 376.50 366.00 285.00 0.00 1608.25
83 Paladin* 0.00 0.00 0.00 0.00 0.00 313.75 313.75

Why do my Challenge Stats get split just because I changed my Name from PoorBoy to Paladin*. I'm still using the same E-Mail Address so the Stats should go under my Current Name I would think, if not then the whole Challenge Year has been a waste for me ... :(

I sent John a PM about it David, I noticed at least 1 other person messed up the same way as I know the 2 different names were the same person ...

Another example:
[BOINC@Poland] ksysju
ksysju
____________

I suspect it is because the results are compiled in partly manual fashion and the name change was not noticed. I suggest a PM to John to fix this.

Think I'll Change my name to Shanky123 ... LOL ... Thanks for fixing mine John ... ;)

Think I'll Change my name to Shanky123 ... LOL ... Thanks for fixing mine John ... ;)

This is the first notice to everyone that 321 sieve is approaching optimal depth for the n<25M range.

Eek! Time to drop everything and start crunching if I want a silver badge. My calculations show I can get there in 20 days. For how much more time do you see 321 Sieve continuing, based on normal non-challenge rates?

Only after rebooting AND aborting some suspended tasks (which I planned to complete after the challenge) AND changing prefs to "No GPU Tasks" did it finally decide to request more CPU tasks. - Can anyone explain to me the weird logic behind Boinc-Manager's decisions on when to request new tasks??

This is the first notice to everyone that 321 sieve is approaching optimal depth for the n<25M range.

Eek! Time to drop everything and start crunching if I want a silver badge. My calculations show I can get there in 20 days. For how much more time do you see 321 Sieve continuing, based on normal non-challenge rates?

At least 6 months to a year out. We are 70% towards "optimal" so there's still plenty of time to get those badges. This is just first notice. :)

If what you need to suspend is less than 10 days worth, you can increase your cache to 10.0 days worth and still get new tasks if the are short time frame (requested + suspended < 10.0 days).
____________
Murphy (AtP)