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1) Message boards : Generalized Fermat Prime Search : Scheduler (Message 144867)
Posted 172 days ago by Profile MeFigaYoma
I was curious about how often not prefetching tasks helps to get a 1st, so I looked at the range including my most recent 100 validated workunits for which I got 1st (without prefetching) for GFN-16. They take me about 5:11 each.

216 total WUs
118 (54.6%) 1st (or still pending), and would have been 1st even if I had prefetched (that is, I returned task at least 2:30 before wingman)
89 (41.2%) 2nd
9 (4.2%) 1st, but would have been 2nd had I prefetched (that is, I returned task less than 2:30 before wingman)

Conclusion: for roughly 95% of workunits, the server decides who gets 1st.

I'm not certain how this scales to longer tasks.

Edit: I looked at BOINC manager as a task was completing, and it seemed to take roughly 8 seconds between completing one task and starting the next. This is about 2.6% of the time it takes me to complete one task, so if I had prefetched, I would have been able to do an extra 5 WUs in the time it took to do the 216 above. Maybe better to turn it back on...less selfish too...
2) Message boards : Problems and Help : Genefer22 will be out of time long before finishing. (Message 144863)
Posted 173 days ago by Profile MeFigaYoma
Deadline will automatically extend up to 84 days as long as you keep contacting the server.

I have not tried those tasks myself, but from what I understand, they really do take that long. PrimeGrid preferences says recent average CPU time is 1128 hours (= 47 days). Most people only run these on GPU.
3) Message boards : Problems and Help : Tasks fetched 2 minutes before previous ends (Message 144725)
Posted 177 days ago by Profile MeFigaYoma
Setting "Max # of simultaneous PrimeGrid tasks" in PrimeGrid preferences to the number of active tasks you want seems to prevent task prefetching.
4) Message boards : Number crunching : √Čvariste Galois's Birthday Challenge (Message 144202)
Posted 188 days ago by Profile MeFigaYoma
Hello, I've been away from PrimeGrid for a bit due to only having a laptop available for some time. I recently acquired a Ryzen 3600XT, and I'm a little confused about the new multithreading settings.

Prime95 64-bit version 30.3, RdtscTiming=1
Timings for 384K all-complex FFT length (6 cores, 1 worker): 0.28 ms. Throughput: 3520.39 iter/sec.
Timings for 384K all-complex FFT length (6 cores, 2 workers): 0.41, 0.40 ms. Throughput: 4947.41 iter/sec.
Timings for 384K all-complex FFT length (6 cores, 3 workers): 0.64, 0.73, 0.60 ms. Throughput: 4630.21 iter/sec.
Timings for 384K all-complex FFT length (6 cores, 6 workers): 1.12, 1.14, 1.13, 1.14, 1.16, 1.13 ms. Throughput: 5287.88 iter/sec.
Timings for 384K all-complex FFT length (6 cores hyperthreaded, 1 worker): 0.30 ms. Throughput: 3300.74 iter/sec.
Timings for 384K all-complex FFT length (6 cores hyperthreaded, 2 workers): 0.37, 0.37 ms. Throughput: 5384.34 iter/sec.
Timings for 384K all-complex FFT length (6 cores hyperthreaded, 3 workers): 0.53, 0.60, 0.54 ms. Throughput: 5370.18 iter/sec.
Timings for 384K all-complex FFT length (6 cores hyperthreaded, 6 workers): 1.03, 1.03, 1.05, 1.03, 1.04, 1.04 ms. Throughput: 5784.13 iter/sec.

It says in this thread's first post that multithreading is recommended, yet I still seem to get better results running one task per core. Is this because of the large cache size of the new processors?

The result for the 6 cores, 3 workers test looks a little strange. Is this because of cache boundaries or something similar?

Also, I'm a bit puzzled by the apparent increase in performance when hyperthreading is used. Last time I checked, hyperthreading was always supposed to be disabled for LLR, but now I seem to get a ~10% performance increase with hyperthreading enabled, at least with the Prime95 benchmark. This also comes with a ~15% power consumption increase, however, and this processor already runs hot, even with a good cooler.

Are these results normal, specific to the new Ryzens, or is there something unusual with my setup?
5) Message boards : General discussion : Why are you appearing on Android now? (Message 97681)
Posted 1712 days ago by Profile MeFigaYoma
As far as I can remember, it was already broken when I joined, so maybe it should be taken off the projects list until somebody actually fixes it. Otherwise some people might get confused why they can add the project, but not get any tasks.
6) Message boards : Number crunching : trying to download ocl (Message 97663)
Posted 1712 days ago by Profile MeFigaYoma
I definitely don't know the answer to your problem, but whoever does will need to know what subproject you're trying to run ;)
7) Message boards : Number crunching : 2016 PrimeGrid Challenge Series ideas (Message 97640)
Posted 1713 days ago by Profile MeFigaYoma
If AP27 is not ready or stable, let's run 321 since it was not run last year.

Also a good idea.
8) Message boards : Generalized Fermat Prime Search : GFN21 wu lost? (Message 97567)
Posted 1715 days ago by Profile MeFigaYoma
SOB wu is a triple check. I don't care about getting credits anymore. Should I abort it too, right? A rhetorical question, I think.

I've had it happen before where a double-checker returned a task a week after it timed out, wasting my 50% progress on the WU. But somebody has to do these tasks, and when you do complete them, you get that sweet 60% credit bonus. Some projects have much longer tasks, but I think most of them don't have immediate double checks, so that makes the frustration a little lower. I wouldn't want to do any Primegrid task that took 1000 hours.

Not sure why the GFN WU restarted from the beginning.
9) Message boards : Extended Sierpinski Problem : ESP-Sieve to shut down on July 31st (Message 97388)
Posted 1724 days ago by Profile MeFigaYoma
Well, I almost got that jade badge. 532k credits shy in the end (a day and a half's work); I really miss that extra 6 core (c'mon Asus, hurry up!).

Is there any reason you couldn't set up a queue to download enough workunits to get your badge? That's what I did; it turned out to not be necessary, so I aborted all the WU's I hadn't started yet to let other people finish up their badges.

Should have asked for a little help from the community. At WCG, a thread is created whenever a project is about to end, where people can request help to get that little push they need to achieve a badge.

How would you "help" someone else to achieve a badge? Do you connect your computer to their account with the weak account key or something?
10) Message boards : Number crunching : GTX 660 gpu for primegrid (Message 97321)
Posted 1727 days ago by Profile MeFigaYoma
Do whatever you want. As far as GPUs go, yours would be more efficient at PPS sieve than GFN. However, there are already tons of people doing PPS sieve for the credit on n-ranges that we aren't going to get to in years (decades?), so if you want to do something more current/want to find primes do GFN. I hear there are also some GPU projects in the Project Staging Area. There's also manual GFN sieving, not sure if that works the same as PPS sieve as far as which GPUs are more efficient.


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