Welcome to the Ides of March

PrimeGrid's Challenge series continues with the "Ides of March Challenge". Once again we observe Caesar's demise by finding factors that will bring some k/n pairs to their demise (thus we won't have to primality test them). Traditionally, this is also a time to honor the sievers...because without them, prime finding with these large numbers would be next to impossible.

Many may not know but in 2007, this was PrimeGrid's first Challenge. It is wonderful to see how the Challenges have grown! This has only been possible through participants like you. Thank you!!!

A 24 hour Challenge is being offered on PrimeGrid's Prime Sierpinski Project/Seventeen or Bust (Sieve) application.

To participate in the Challenge, please select only the PSP/SoB (Sieve) project in your PrimeGrid preferences section. The challenge will begin 15 March 2010 18:00 UTC and end 16 March 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 PSP/SoB (Sieve) application requires a one time download of a 10MB sieve file. Please consider running a few PSP/SoB (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 15 March 2010 18:00 UTC and received BEFORE 16 March 2010 18:00 UTC will be considered for credit. Since this is a fixed credit project, we'll be using cobblestones for scoring.

About the Sierpinski Problem

Waclaw Franciszek Sierpinski (14 March 1882 - 21 October 1969), a Polish mathematician, was known for outstanding contributions to set theory, number theory, theory of functions and topology. It is in number theory where we find the Sierpinski problem.

Basically, the Sierpinski problem is "What is the smallest Sierpinski number" and the prime Sierpinski problem is "What is the smallest 'prime' Sierpinski number?"

First we look at Proth numbers (named after the French mathematician François Proth). A Proth number is a number of the form k*2^n+1 where k is odd, n is a positive integer, and 2^n>k.

A Sierpinski number is an odd k such that the Proth number k*2^n+1 is not prime for all n. For example, 3 is not a Sierpinski number because n=2 produces a prime number (3*2^2+1=13). In 1962, John Selfridge proved that 78,557 is a Sierpinski number...meaning he showed that for all n, 78557*2^n+1 was not prime.

Most number theorists believe that 78,557 is the smallest Sierpinski number, but it hasn't yet been proven. In order to prove it, it has to be shown that every single k less than 78,557 is not a Sierpinski number, and to do that, some n must be found that makes k*2^n+1 prime.

The smallest proven 'prime' Sierpinski number is 271,129. In order to prove it, it has to be shown that every single 'prime' k less than 271,129 is not a Sierpinski number, and to do that, some n must be found that makes k*2^n+1 prime.

Seventeen or Bust is working on the Sierpinski problem and the Prime Sierpinski Project is working on the 'prime' Sierpinski problem. The following k's remain for each project:

• Prime Sierpinski Project
  
• Seventeen or Bust
  

For more information about Sierpinski, Sierpinski number, and the Sierpinsk problem, please see these resources:

• Waclaw Franciszek Sierpinski (WIKI)
  
• Sierpinski number / The Sierpinski problem (WIKI)
  
• The Sierpinski problem (Prothsearch)
  

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. :)

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 9.10 (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.
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OK
I am running Ubuntu 9.10 and have a Phenom 9650 X4 [no dual boot]
The above instructions will give me the icon. The preference section is currently
set to Ondemand and the Frequency syitches from 2.30 GHz to 1.15 GHz.
Are you telling me that it would be better to switch to Preformance instead?

BOINC is running / crunching SoB and PPS-sieve.
But because of a quirk in the system it will not run at peak without the change?
It is just sitting there crunching and "yawning" instead of work hard at the crunching?

OK I have all 4 cores listing Performance.

Since it is a desktop, I wonder how much it will effect the system.

Clarification! - PSP/SoB (Sieve)

This is just a friendly reminder that the upcoming "Ides of March Challenge" is on the PSP/SoB (Sieve) application. This sieve supports both the Prime Sierpinski Problem and Seventeen or Bust projects. With the recently added projects over the past six months things can be a little confusing. The following could be mistaken for the Challenge:

Prime Sierpinski Problem (LLR)
Seventeen or Bust (LLR)

However, the WU's in the above LLR projects take several days to complete...simply not suitable for a 24 hour Challenge. :) The Challenge is NOT on these LLR projects.

Therefore, please review your PrimeGrid preferences page and make sure you familiarize yourself with the project selections. Again, the upcoming "Ides of March Challenge" is on the PSP/SoB (Sieve) application.

Please run a few WU's from PSP/SoB (Sieve) ahead of time so that your hosts will already have the sieve file. This will free up resources at the beginning of the Challenge to deliver WU's instead of sieve files.

Thank you and Good Luck!
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Perhaps the PrimeGrid preferences webpage could be modified with big bold blinking letters saying

"*THIS* is the project for the Ides of March Challenge"?
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Perhaps the PrimeGrid preferences webpage could be modified

Perhaps the PrimeGrid preferences webpage could be modified

Good suggestion. Done. :)

PrimeGrid preferences

Very good move - thanks John!
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The latest version of Ubuntu is v.9.10

http://www.ubuntu.com/

FYI...this note was added to the first post.

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.
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I'm still running 9.04, and while my cores run at full speed while I'm at stock speed, when I overclock the FSB to 400MHz, they tend to get stuck slower until I set them to Performance. Twice! I don't think it's a stability issue; I overclocked for the last challenge and only got one invalid LLR result. I think it's just a bug somewhere.

But I don't know if it's still an issue with 9.10. (I had trouble upgrading; I'm going to try starting fresh with 10.04.)
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How to Join the Challenge

To participate in the Challenge, please select only the PSP/SoB (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 15 March 2010 18:00 UTC and end 16 March 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 PSP/SoB (Sieve) application requires a one time download of a 10MB sieve file. Please consider running a few PSP/SoB (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 15 March 2010 18:00 UTC and received BEFORE 16 March 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 (15 March 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 200K. At the start of the Challenge, these settings will be adjusted as necessary. However, if the past year is any indication, 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 3 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 a good 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 and only select PSP/SoB (Sieve) project
  -At worse, you'll only be 1 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 PSP/SoB (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 PSP/SoB (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!
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24 hours to go!!!

The k/n pairs in the sieve file have been warned against a great peril on the Ides of March. Yet they arrogantly hang around hoping to be proven prime. Well, in less than 24 hours, that hope will be replaced with sheer fright as the "senators" of PrimeGrid seek their demise.

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 to allow the server to send and receive work.

What to expect at Challenge start

The server always gets hit hard at the beginning of the Challenge. However, a procedure that we've been using for all the Challenges this year has been very successful so far, and we hope it holds true for the final Challenge. A few hours before the start (15 March 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 load at least 200K+ into the buffer. At the start of the Challenge, these settings will be adjusted as necessary. Historically, the first adjustment happens 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 3 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 10 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.
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Hey Ho, Lets Go!
I have booted up all of my relevant clients, will join in with my old Core Duo Lenovo Thinkpad T60p later on...
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same here despite:

Available: PSP/SoB (Sieve) 295904

same here despite:

Available: PSP/SoB (Sieve) 295904

What's going on here? I have my account set to take only PSP Sieve WUs, but the server just told me there are no PSP Sieve WUs available, and sent me some of everything else.

I figured that the server might have issues, but shouldn't there be an ample supply of WUs in the first minute of the challenge?

Running OK now...at least on my side.
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15 minutes in and i can't get a single WU. this is rediculous.

Of three boxes I'm running, two of them got WUs on the first try; the third got the "No PSP (Sieve) available" error message. At the time there were around 300,000 WUs available.

Automatic retry a minute later succeeded in grabbing some WUs.


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It is better now but the two nehalems are behaving very strange, "for an aditional" is set to 0.2 but they have 8 WUs running and only do request additional WUs for GPU...

EDITH says the have problems with client-specific preferences...

20 minutes, 26K WU's sent out.

EDIT: 25 minutes, 28K WU's sent out. Looks like demand is slowing down.
EDIT: 30 minutes, 30K WU's sent out. Definitely leveled off.
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Looks like demand is slowing down.

A loud, piercing screech and small puff of smoke... say good bye to a hard drive.

Ten seconds of silence, please.

100K tasks sent out at 2 hours.
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Challenge Update

We are now at the following settings:

Max cache: 40 tasks per core
Max send: 16 tasks per core

This should give most hosts a full cache to finish the next 20+ hours of the challenge. In a few hours, expect to see a small decrease in Max cache as we start preparing for the finish.

We are definitely on pace to surpass the previous PSP/SoB (Sieve) Challenge output. We'll have to wait until the end to see by how much.

There's definitely a lot of tight races going on. Best of Luck to everyone.

Participants | Teams

Speaking of Luck, check out the St. Patrick's Day Parade. If you have ever participated in the Riesel problem, it's a great place to go for a day after the Challenge. At the end of the Challenge, just switch from PSP/SoB (Sieve) to The Riesel Problem (Sieve) in your PrimeGrid preferences section. With a good showing there, we'll be able to start up LLR to complete the FULL return of the Riesel problem.

Again, good luck on the Challenge and hope to see you at the parade.
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off topic: Are there any plans for AP26 to support ATI GPUs?

Only 3 hours remain!

Now's the time to start preparing for the end of the Challenge. Please remember to upload early and often. The server is going to get hit hard as the Challenge draws to an end. We have started lowering "max cache" to help with this.

Only work units issued AFTER 15 March 2010 18:00 UTC and received BEFORE 16 March 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".

Good Luck to everyone as we finish these last 3 hours...

Speaking of Luck, check out the St. Patrick's Day Parade. If you have ever participated in the Riesel problem, it's a great place to go for a day after the Challenge. At the end of the Challenge, just switch from PSP/SoB (Sieve) to The Riesel Problem (Sieve) in your PrimeGrid preferences section. With a good showing there, we'll be able to start up LLR to complete the FULL return of the Riesel problem.

Again, good luck on the Challenge and hope to see you at the parade.
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All work done, will run dry my cache now on all clients that are only powered on for the challenge.
Seems like i have done 1223 WUs.

Finished!!!

The Ides of March Challenge has completed. The "senators" have succeeded in bringing down many k/n pairs. As soon as the dust settles, we'll be back with preliminary results.

When the results come in, this will be the best performance on a PSP/SoB (Sieve) Challenge. Well done everyone. Thank you for participating in the Challenge.

Since there will be no need for a "clean-up", please consider hanging around a couple of extra days on the the Riesel Problem (Sieve) and participating in the St. Patrick's Day Parade. The parade will begin 17 March 00:00 UTC and end 18 March 00:00 UTC. With a good showing there, we'll be able to start up TRP (LLR).

Hope to see you there!
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The results are Final!

"Et tu, Brute?" Yes, even Brutus stopped by and took down a few k/n pairs. He and the rest of the "senators" did the dirty work of rounding up the prime wannabes and placing them forever in the realm of composites. While they won't make the same notoriety as Caesar did, they will still rest in peace.

Again, another Challenge in which an incredible amount of work was completed. This PSP/SoB (Sieve) Challenge almost doubled the output of the last one with just over p=1.01P sieved in the 24 hours of the Challenge. Over 336K tasks were returned resulting in almost 10M cobblestones awarded.

Over 400 factors were found. At this sieve depth (~70P), that's an excellent accomplishment. 169 teams and 1299 individuals participated in the Challenge.

The Challenge Points stats will be updated soon. Congratulations to SETI.USA as the top team and shanky as the top individual.

Thank you again to everyone. We appreciate your participation and hope you had fun!

If you are able to hang around for another 24 hours, check out the St. Patrick's Day Parade on The Riesel Problem (Sieve). The parade will begin 17 March 00:00 UTC and end 18 March 00:00 UTC. With a good showing there, we'll be able to start up TRP (LLR).

Stats: Participants | Teams

Jim, "P" is an SI prefix. It means 10 to the 15th power.

So 70P means 70,000,000,000,000,000, or 70 quadrillion - at least in the USA. 70P is shorter, and clearer in countries where the roles of ',' and '.' are reversed, or where quadrillion means 10^24!
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It means that all candidates in the sieve file have been tested for factors up to 70P. So none of the remaining candidates have factors smaller than 70P.
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There are only 10 kinds of people - those who understand binary and those who don't