PrimeGrid
File:Primegrid logo.png PrimeGrid logo | |
Original author(s) | Rytis Slatkevičius |
---|---|
Initial release | June 12, 2005[1] |
Platform | Cross-platform |
Available in | English |
Type | Distributed computing |
Website | primegrid.com |
PrimeGrid is a distributed computing project for searching for prime numbers of world-record size. It makes use of the Berkeley Open Infrastructure for Network Computing (BOINC) platform. As of April 2010[update], there are about 6,100 active participants (on about 14,000 host computers) from 100 countries with a total BOINC credit of more than 2.7 billion, reporting about 72 teraflops (72 trillion operations per second) of processing power.[2]
History
PrimeGrid started in June 2005[1] under the name message@home and tried to decipher text fragments encrypted with MD5. Message@home was a test to port the BOINC scheduler to Perl to obtain greater portability. After awhile the project attempted the RSA factoring challenge trying to factor RSA-640. After RSA-640 was factored by an outside team in November 2005, the project moved on to RSA-768. With the chance to succeed too small, it discarded the RSA challenges, was renamed to PrimeGrid, and started generating a list of the first prime numbers. At 210,000,000,000[3] the primegen subproject was stopped.
Primegrid then worked with the Twin Prime Search to search for a record-sized twin prime at approximately 58700 digits. The new worlds largest known twin prime 2003663613 × 2195,000 ± 1 was eventually discovered on January 15, 2007 (sieved by Twin Prime Search and tested by PrimeGrid). The search continued for another record twin prime at just above 100,000 digits. It was completed on August 2009 when Primegrid found 65516468355 × 2333,333 ± 1.
Projects
As of April 2010[update], PrimeGrid is working on or has worked on the following projects:
Project | Active sieve project? | Start | End | Best result |
---|---|---|---|---|
321 Prime Search (primes of the form 3×2n±1) | Yes | 30 June 2008 | Ongoing | 3×25082306+1[4] |
AP26 Search (Arithmetic progression of 26 primes) | N/A | 27 December 2008 | 12 April 2010 | 43142746595714191 + 23681770×23#×n, n = 0…25 (AP26) |
Cullen Prime Search | Yes (with Woodall) | August 2007 | Ongoing | N/A |
Message7 | No | 12 June 2005 | August 2005 | PerlBOINC testing successful |
Prime Sierpinski Problem | Yes (with Seventeen or Bust) | 10 July 2008 | Ongoing | N/A |
PrimeGen | No | March 2006 | February 2008 | |
Proth Prime Search | Yes | 29 February 2008 | Ongoing | 659×2617815+1, divides F617813[5] |
Riesel Problem | Yes | March 2010 | Ongoing | N/A |
RSA640 | No | August 2005 | November 2005 | N/A |
RSA768 | No | November 2005 | March 2006 | N/A |
Seventeen or Bust | Yes (with Prime Sierpinski Problem) | 31 January 2010 | Ongoing | N/A |
Sophie Germain Prime Search | No | 16 August 2009 | Ongoing | N/A |
Twin Prime Search | No | 26 November 2006 | 25 July 2009 | 65516468355×2333333±1, largest known twin primes[6] |
Woodall Prime Search | Yes (with Cullen) | July 2007 | Ongoing | 3752948×23752948−1, largest known Woodall prime[7] |
Accomplishments
As of 4 January 2008[update], the project has discovered the three largest Woodall primes known to date.[8] The largest of these, 3,752,948 × 23,752,948 − 1, is the first mega prime discovered that is also a Woodall prime and is 1,129,757 digits long. It was discovered on December 21, 2007 by Matthew J Thompson using the LLR program.[9] The search for an even bigger Woodall prime continues. PrimeGrid also found the largest known generalized Woodall prime[10].
Since September 2008, PrimeGrid is also running a Proth prime sieving subproject.[11]
PrimeGrid is also running a search for Cullen prime numbers, yielding the two largest known Cullen primes. The first one being the 14th largest known prime at the time, and the second one is PrimeGrid's largest prime found 6679881 · 26,679,881+1 at over 2 million digits[12]. Further PrimeGrid is helping 3*2^n-1 Search project search for primes, testing for a record Sophie Germain prime and sieving for Prime Sierpinski Project.
Another PrimeGrid project is AP26 Search which searches for a record 26 primes in arithmetic progression. The search was successful in April 2010 with the finding of the first known AP26: 43142746595714191+23681770*23#*n prime for n=0..25[13].
In January of 2010 the subproject Seventeen or Bust was added[14]. The calculations for the Riesel problem followed in March 2010.
References
- ^ a b PrimeGrid's Challenge Series - 2008 Final Standings
- ^ "Detailed user, host, team and country statistics with graphs for BOINC", boincstats.com, retrieved 2010-02-01
- ^ Download Prime Lists
- ^ http://www.primegrid.com/download/321-5082306.pdf
- ^ http://www.primegrid.com/download/PPS-F617815.pdf
- ^ http://www.primegrid.com/download/Twin333333.pdf
- ^ http://www.primegrid.com/download/Woodall3752948.pdf
- ^ The Prime Pages; The Top Twenty: Woodall Primes
- ^ "PrimeGrid" website
- ^ The Prime Pages; The Top Twenty: Generalized Woodall
- ^ PrimeGrid forum: PPS Sieve
- ^ The Prime Pages; The Top Twenty: Cullen Primes
- ^ PrimeGrid forum: First ever AP26 found
- ^ PrimeGrid forum: Seventeen or Bust and the Sierpinski Problem
External links
- PrimeGrid
- "Spreading the load". The Economist. 6 December 2007. Retrieved 8 February 2010.