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1) Message boards : Number crunching : Transit of Mercury Across the Sun Challenge (Message 134414)
Posted 36 days ago by Profile pschoeferProject donor
Will you be able to see the transit with the naked eye, using appropriate protection as you would for a solar eclipse? Or is Mercury too small?

EDIT: Nope, it's too small to see the transit without some type of telescope or binoculars or something else to magnify the image.

There are claims that sunspots as small as 10-12 arcsec have been seen with just the naked eye and the usual solar eclipse goggles. Mercury can reach up to 12 arcsec during a transit and has an even higher contrast than the darkest sunspots, so it might just be possible. However, 12 arcsecs are only reached if the transit happens in May (like the last one in 2016), while it's more like 7 arcsec for a transit in November.

Fun fact: Most people who are familiar with our Solar System's planets might think that Venus or maybe Mars is the planet closest to Earth. However, it turns out that -on average- Mercury is our closest neighbor.
2) Message boards : Number crunching : Suggestions for 2020 Challenges (Message 134098)
Posted 46 days ago by Profile pschoeferProject donor
There hasn't been a non-LLR CPU challenge since January 2017, so 321-Sieve should definitely be on the list for next year. Similarly, the small and medium-size GFN projects haven't seen a challenge for a while. Even if you want to run another large GFN challenge on the primeless Ns, there's still enough room for a second GFN challenge, especially if AP27 is shut down leaving PPS-Sieve as the only other GPU option.

I'd also like to see a return of the 3-day challenges. There are still several short-task projects left and a 5d+ challenge just gets boring pretty fast when even leftover machines from the last decade can still finish several tasks per day.

It might also be a good idea to leave the project open for one or two challenges in the second half of the year. That makes it easier to take unforeseen circumstances -e.g., a new project like PPS-DIV this year- into account without crowding the calendar even further or stepping on anyone's toes.
3) Message boards : AP26 - AP27 Search : sporadic crashes on AMD GPUs (access violation) (Message 133107)
Posted 75 days ago by Profile pschoeferProject donor
For the ongoing challenge, I also threw my AMD GPUs at AP27. While they finish most tasks slowly but reliably, every GPU had at least one task crashing after a few seconds with error code -1073741819 (0xC0000005) STATUS_ACCESS_VIOLATION. A few examples:

1025750645 (RX 590)
1025834999 (RX 580)
1025739021 (R9-280X)
1025941747 (another R9-280X)

This should rule out a hardware problem, but all machines are using the same version of the driver software (19.8.1 on Win10 1903), so I can't tell if the problem is in that specific driver or the AP27 app itself.

Is anyone else seeing those crashes on their AMD GPUs?
4) Message boards : Fermat Divisor Search : Fermat Divisor Search (Message 132630)
Posted 91 days ago by Profile pschoeferProject donor
Second phase is searching 5<=k<=49 up to 9M. This part will take longer.

Does that include k=27? If so, are we doublechecking the results of the ongoing PRPNet effort or just skipping to n>7.5M for that k?
5) Message boards : Generalized Fermat Prime Search : DO YOU FEEL LUCKY? (Message 131666)
Posted 126 days ago by Profile pschoeferProject donor
an " Option " … which is aplied … in MilkyWay@Home and in GpuGrid … maximum CPU for Graphics

That's a very old BOINC standard setting that you will find at all projects without a customized settings page. It is a screensaver setting (i.e., graphics output) and has nothing to do with GPU applications.
6) Message boards : Number crunching : 50th Anniversary of the Moon Landing Challenge (Message 131290)
Posted 140 days ago by Profile pschoeferProject donor
Is "13 primes have been found so far!" normal for this Event or do we see more most of the time?
"1 xGFN divisor!" I think this was me.
Now I know what that is...Divides xGF(2750266,7,4)
T5K, https://primes.utm.edu/primes/page.php?id=126656
701*2^2750267+1 is a Factor of xGF(2750266,7,4)!!!! (10616.880000 seconds)


It's been a long time since we've run a PPS challenge. What I can say is participation is very high, and we're crunching a whole lot of tasks. We had been doing about 16K tasks per day before the challenge, and now we're doing close to 200K per day.

Last year's Solar Eclipse Challenge was at PPS-LLR. Back then, ~145k tasks per day were completed successfully and 9 primes were found in 3 days. So we're doing ~35% more (and slightly longer) tasks this time and might also end up with more primes per day.
7) Message boards : Number crunching : 2019 Tour de Primes (Message 126789)
Posted 297 days ago by Profile pschoeferProject donor
Found a second PPSE prime this month. I was wondering what the additional text meant on the find: 6885*2^1521067+1 is a Factor of xGF(1521065,11,5)!!!! (1711.170000 seconds)

Your prime divides the (huge) extended Generalized Fermat number 2^11^1521065+2^5^1521065.

Every Proth prime might be an xGF, GF, or even Fermat number divisor. Last year, only 10 xGF divisors were found (among 497 primes of Proth form), so they are less common than new Top 100 primes nowadays. The most recent GF divisor was found in August 2017, the most recent Fermat number divisor back in February 2015.
8) Message boards : Number crunching : 2019 Tour de Primes (Message 126270)
Posted 304 days ago by Profile pschoeferProject donor
I did check the 2018 TdP leaderboard, and unless I counted wrong, 3 of the 28 days didn't have any GFN prime discoveries.

3 days without any GFN discovery, and another day without a GFN-16 but a GFN-17-Low instead. The rate of PPSE discoveries also varies a lot. Despite the average of 6 PPSE primes per day last year, there was one day with only one PPSE prime:

9) Message boards : AP26 - AP27 Search : Geforce Drivers 4xx.xx Drop more than 2/3 in OpenCL Performance from the 3xx.xx Drivers. (Message 125645)
Posted 310 days ago by Profile pschoeferProject donor
No problems with version 2.04 on my AMD RX 590 + NVIDIA GTX 1070 Ti and AMD R9-280X + NVIDIA GTX 1070 machines. No significant change in run time. The NVIDIA tasks, however, used significantly less CPU time.
10) Message boards : AP26 - AP27 Search : Geforce Drivers 4xx.xx Drop more than 2/3 in OpenCL Performance from the 3xx.xx Drivers. (Message 125525)
Posted 312 days ago by Profile pschoeferProject donor
The new Windows app is working on both my AMD RX 590 + NVIDIA GTX 1070 Ti machine and my AMD R9-280X + NVIDIA GTX 1070 machine (both running Windows 10 x64).

I can also confirm that the performance drop is fixed, run time is the same with 416.34 as with 399.24.


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