Welcome to Suzuki's Birthday Challenge: 5 day GFN-19 from October 2 17:00 UTC to October 7 17:00 UTC

On the occasion of the 100th birthday of renowned group theorist Michio Suzuki, PrimeGrid will host a 5-day challenge on the GFN-19 project. The Generalized Fermat Number project is a sub-project of PrimeGrid that tests the primality of numbers of the form b^n + 1, where b is an even integer and n is an integer that is a power of 2. The GFN-19 sub-project tests numbers where n = 2^19.

To participate in the challenge:

• Wait until the challenge timeframe starts (or set your BOINC Client download schedule accordingly), as tasks issued before the challenge will not count.
  
• In your PrimeGrid preferences section, select only the GFN-19 project.
  

Important reminders:

• Note on GFN tasks: GFN has eliminated the need for a full doublecheck task on each workunit, but has replaced it with a short verification task. Expect to receive a few tasks about 1% of normal length.
  
• The typical deadline for some of these WUs is longer than the challenge time-frame, so make sure your computer is able to return the WUs within 7 days. Only tasks issued AFTER the start time and returned BEFORE the finish time will be counted.
  
• At the Conclusion of the Challenge: 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 a 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. Thanks!

Let's talk about hardware:

Supported platforms for GFN tasks:


• Windows: CPU¹: x86, x64. GPU²: Nvidia, AMD, Intel ARC.
  
• Linux: CPU¹: x86, x64, ARM64. GPU²: Nvidia, AMD, Intel ARC.
  
• Mac: CPU¹: x64, ARM64. GPU²: Nvidia, AMD, Apple M-Series.
  
• For CPU tasks, multi-threading is supported and IS recommended. Click here to set the maximum number of threads.
  
• All GFN use fast proof tasks so no double check tasks are needed. Everyone is "first"!
  
  ¹ CPU tasks are not available for GFN-15 (n=32768) or "Do You Feel Lucky?".
  ² OpenCL 1.1 or higher is required.


GFN-18 WU's are currently averaging 12 hours on CPU and 21 minutes on GPU.
GFN-19 WU's are currently averaging 2 days on CPU and 1 hours on GPU.
GFN-20 WU's are currently averaging 6 days on CPU and 3 hours on GPU.
For a general idea of how your GPU stacks up, you can have a look at the fastest GPUs list.

As with all number crunching, excessive heat can potentially cause permanent hardware failure. Please ensure your cooling system is sufficient. Please see this post for more details on how you can "stress test" your CPU, and please see this post for tips on running GFN on your GPU successfully.
IMPORTANT: Overclocking -- including factory overclocking -- on Nvidia GPUs is very strongly discouraged. Even if your GPU can run other tasks without difficulty, it may be unable to run GFN tasks when overclocked.

Additional information:

Time zone converter:
from October 2 17:00 UTC to October 7 17:00 UTC
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.

Scoring Information
Scores will be kept for individuals and teams. Only tasks issued AFTER October 2 17:00 UTC and submitted BEFORE October 7 17:00 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.

More information on Generalized Fermat Numbers and the Genefer program

• Generalized Fermat Number Search Forum
  
• Wikipedia: Generalized Fermat Numbers
  
• Wikipedia: Pierre de Fermat
  
• Yves Gallot's Generalized Primes Search pages