Same exponent assigned twice for P-1
 

I have two Colab notebooks which have been assigned the same exponent for P-1 factoring (102953047). One is currently at 59% of stage 1 and the other at 41% of stage 1.

I'm not sure if this is the right place to ask.

Up until now, I've been getting TF work for my GPU from the primenet website. I've now tried to get work from GPU to 72, and it looks like very, very different work.

I was getting TF to 73 for exponents around 110M, while GPU to 72 gives me exponents to 77 for factors around 96M.

I'm not sure I understand the rationale between one kind of work vs the other, and which is "better" (as in, saves more time for primality checking? I think that's the simplest good metric to measure in this case, but I'm not sure I understand everything about primenet yet).

I will note that after 1000GHz/d of manual testing TF work from primenet, I haven't found a factor yet. (now that I've upgraded my GPU to a 1650 things should move along faster, I think)

[QUOTE=EugenioBruno;539278]I'm not sure if this is the right place to ask.

I will note that after 1000GHz/d of manual testing TF work from primenet, I haven't found a factor yet. (now that I've upgraded my GPU to a 1650 things should move along faster, I think)[/QUOTE]

Sometimes I find several factors in a day, other times I go a month without finding any.

haha, just a few checks after reading your message, after 200 or so total TFs, I finally found a factor! :)

[url]https://www.mersenne.org/report_exponent/?exp_lo=109373191&full=1[/url]

[QUOTE=Uncwilly;539252]I noticed that there was a factor found by a P-1 instance that is on my GPU72 graph, but the one for the TF factor found within 24 hours of it is not on the graph. Both of theses are in the last 48 hours.[/QUOTE]

Hey... OK, quickly catching up...

This is a small bug introduced by the Colab auto-submitter... The Factor Found code path doesn't insert the factor into a table. The system does know a factor is found, but some of the reports reference the aforementioned table.

This is trivial to fix; no data is lost -- I'll be able to have the system back-fill the missed entries. This week.

[QUOTE=linament;539262]Thought I would pass this on, one of my GPU72 Colab assignments received a result not needed message from PrimeNet today when I reported it. [URL="https://www.mersenne.org/M107578847"]M107578847[/URL] (272-273).[/QUOTE]

OK. Thanks for the report.

I'm afraid this is an example of a "friend" TF'ing "off the books". He doesn't respect the assignments as officially issued by Primenet (some of which GPU72 simply "lends" out to participants to work), and so he occasionally steps on toes.

I'm afraid there's nothing I can do about this, beyond pleading that he not do it...

[QUOTE=Chuck;539277]I have two Colab notebooks which have been assigned the same exponent for P-1 factoring (102953047). One is currently at 59% of stage 1 and the other at 41% of stage 1.[/QUOTE]

Hmmm... OK, thanks for the report. I'll take a look at the logs, and see what I can infer.

In the short term, I've lengthened the recycling period for Colab P-1 assignments. It was twenty (20) minutes; it's now seventy (70).

[QUOTE=EugenioBruno;539278]I was getting TF to 73 for exponents around 110M, while GPU to 72 gives me exponents to 77 for factors around 96M.

I'm not sure I understand the rationale between one kind of work vs the other, and which is "better" (as in, saves more time for primality checking? I think that's the simplest good metric to measure in this case, but I'm not sure I understand everything about primenet yet).[/QUOTE]

Thanks for joining our little group! :tu:

Basically, we have determined that it is "optimal" to TF to 77 bits before running the First Check.

But... That's actually quite a bit of work, and not everyone wants to go that high. And that's perfectly fine. Your kit, your time, your choice.

Thus, GPU72 will let people choose the depth (and, optionally, range) they'd like to "pledge" to work on. All work is valuable, and will be targeted as best benifits the GIMPS goal of finding the next Mersenne Prime! :smile:

[QUOTE=chalsall;539292]The system does know a factor is found, but some of the reports reference the aforementioned table.

This is trivial to fix; no data is lost -- I'll be able to have the system back-fill the missed entries. This week.[/QUOTE]Yeah, I noticed that the table at the top of the Individual Overall Stats page knows about the factors, just not the graph. :tu:

Since my report, another one showed up. I was running about 12% below the predicted number of factors. Now only about 8%. :brian-e:

As always, you are making it easy for us to [STRIKE]abuse[/STRIKE] use resources out there to help. :bow:

Another thing I noticed, when my last Colab session ended, I am pretty sure that I had an incomplete TF assignment. When I was able to restart a Colab GPU session today, that incomplete TF assignment has disappearred.

[QUOTE=linament;539298]Another thing I noticed, when my last Colab session ended, I am pretty sure that I had an incomplete TF assignment. When I was able to restart a Colab GPU session today, that incomplete TF assignment has disappearred.[/QUOTE]

Do you happen to know what the assignment was? And approximate time (UTC please)?

I could drill down on the logs if I knew at least the former; otherwise, there's way too much traffic to look through.

I'm pretty sure the assignment/reassignment code paths are sane. But I'm happy to be proven wrong (so I can fix it).