Zur Teilnahme wählt 321 Prime Search LLR (321) als einziges CPU-Projekt in euren PrimeGrid Einstellungen aus. Das Rennen wird am 16th März 2018, 18:00 UTC beginnen und endet am 23rd März 2018, 18:00 UTC.
Es ist ein PrimeGrid Projekt-Race, d.h., daß nicht gebunkert werden kann. Vorzeitig gezogene Arbeitspakete werden in der Wertung nicht berücksichtigt!
Wer eine app_config.xml für Multiprocessing verwenden möchte, kann folgende Konfiguration nutzen und muß nur jeweils die '4' durch die tatsächliche Zahl der gewünschten CPU-Kerne ersetzen:
Den ausführlichen Einladungstext findet ihr unten im englischen Original:
Zitiert von hier.Year of the Dog
2018 is a Year of the Dog. In Chinese astrology, each year is related to a Chinese zodiac animal according to the 12-year cycle. 2018 is an Earth Dog Year, starting on 16th February 2018 and ending on 4th February 2019. Earth Dog's are Communicative, serious, and responsible in work. Famous Earth Dog's include Madonna and Michael Jackson.
The second Challenge of the 2018 Challenge series is a 7 day challenge to celebrate the Year of the Dog. The challenge is being offered on the 321 Prime Search (LLR) application.
To participate in the Challenge, please select only the 321 Prime Search LLR (321) project in your PrimeGrid preferences section. The challenge will begin 16th March 2018 18:00 UTC and end 23rd March 2018 18:00 UTC.
Application builds are available for Linux 32 and 64 bit, Windows 32 and 64 bit and MacIntel. Intel CPUs with AVX capabilities (Sandy Bridge, Ivy Bridge, Haswell, Broadwell, Skylake, Kaby Lake, Coffee Lake) will have a very large advantage, and Intel CPUs with FMA3 (Haswell, Broadwell, Skylake, Kaby Lake, Coffee Lake) will be the fastest.
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. Tasks on one CPU core will take ~48 hours on fast/newer computers and 6+ days 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.
Highly overclocked Haswell, Broadwell, Skylake, Kaby Lake or Coffee Lake (i.e., Intel Core i7, i5, and i3 -4xxx or better) computers running the application will see fastest times. Note that 321 is running the latest FMA3 version of LLR which takes full advantage of the features of these newer CPUs. It's faster than the previous LLR app and draws more power and produces more heat. If you have a Haswell, Broadwell, Skylake, Kaby Lake or Coffee Lake CPU, especially if it's overclocked or has overclocked memory, and haven't run the new FMA3 LLR before, we strongly suggest running it before the challenge while you are monitoring the temperatures.
Please, please, please make sure your machines are up to the task.
Multi-threading optimisation instructions
Those looking to maximise their computer's performance during this challenge, or when running LLR in general, may find this information useful.
Time zone converter:
- * Your mileage may vary. Before the challenge starts, take some time and experiment and see what works best on your computer.
* If you have an Intel CPU with hyperthreading, either turn off the hyperthreading in the BIOS, or set BOINC to use 50% of the processors.
* Use LLR's multithreaded mode. It requires a little bit of setup, but it's worth the effort. Follow these steps:
- *If you're using a GPU for other tasks, it may be beneficial to leave hyperthreading on in the BIOS and instead tell BOINC to use 50% of the CPU's. This will allow one of the hyperthreads to service the GPU.
- * Create a app_config.xml file in the directory C:\ProgramData\BOINC\projects\www.primegrid.com\ (or wherever your BOINC data directory is located). For a quad core CPU, the file should contain the following contents. Change the two occurrences of "4" to the number of actual cores your computer has.
* After creating the file, click on "Options/Read config files". You should then restart BOINC or reboot.
* The first time BOINC downloads an 321 task, it may act a little strange and download 4 tasks instead of 1. The run times on this first set of tasks may look a bit strange too. This is normal. This will also occur anytime BOINC downloads more than one task at a time. This can be avoided by setting "Use at most [ 1 ] % of the CPUs" before you download 321 tasks. After one task was downloaded, increase the percentage.
* Some people have observed that when using multithreaded LLR, hyperthreading is actually beneficial. We encourage you to experiment and see what works best for you.
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 at the very top, above the countdown clock.
Scores will be kept for individuals and teams. Only tasks issued AFTER 16th March 2018 18:00 UTC and received BEFORE 23rd March 2018 18:00 UTC will be considered for credit. We will be using the same scoring method as we currently use for BOINC credits. 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.
At the Conclusion of the Challenge
About 321 Search
- We kindly ask users "moving on" to ABORT their tasks instead of DETACHING, RESETTING, or PAUSING.
ABORTING tasks allows them to be recycled immediately; thus a much faster "clean up" to the end of an LLR Challenge. DETACHING, RESETTING, and PAUSING tasks causes them to remain in limbo until they EXPIRE. Therefore, we must wait until tasks expire to send them out to be completed.
Please consider either completing what's in the queue or ABORTING them. Thank you.
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
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 (PrimeGrid's finds in bold & linked):
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, 2291610, 2478785, 5082306, 7033641, 10829346
Primes known for 3*2^n-1 occur at the following n (PrimeGrid's finds in bold & linked):
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, 6090515, 11484018, 11731850, 11895718
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 Penne 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: