mersenneforum.org Type of work I'm doing
 Register FAQ Search Today's Posts Mark Forums Read

 2013-06-20, 00:01 #1 Unregistered   3,467 Posts Type of work I'm doing Hi! The Prime95 says I'm working on "Trial Factoring M87471793 to 2^69". Does this mean I don't work on finding a new prime? I know any work counts, but I read in a very old post that there were four types of work you could do. Only one of them were testing for new primes (directly). How is this so, I can't remember choosing any particular assignment? If I really want to test for my own prime, am I able to do so? In such case, what do I do?
2013-06-20, 05:23   #2
Mr. P-1

Jun 2003

7·167 Posts

Quote:
 Originally Posted by Unregistered Hi! The Prime95 says I'm working on "Trial Factoring M87471793 to 2^69". Does this mean I don't work on finding a new prime? I know any work counts, but I read in a very old post that there were four types of work you could do. Only one of them were testing for new primes (directly). How is this so, I can't remember choosing any particular assignment? If I really want to test for my own prime, am I able to do so? In such case, what do I do?
At the moment, you're searching for a small factor. If you find one, then the number is not prime and you will have disposed of that exponent.

If you don't, then what happens next depends upon the type of assignment you have. Have a look at your worktodo.txt file. If the line with 87471793 in it begins with "Test=", then you will go on to test that exponent for primality. If it begins with "Factor=" then you won't, and the exponent will be given to someone else for testing.

2013-06-20, 05:25   #3
Uncwilly
6809 > 6502

"""""""""""""""""""
Aug 2003
101×103 Posts

1051110 Posts

Quote:
 Originally Posted by Unregistered "Trial Factoring M87471793 to 2^69". Does this mean I don't work on finding a new prime? I know any work counts, but I read in a very old post that there were four types of work you could do. Only one of them were testing for new primes (directly). How is this so, I can't remember choosing any particular assignment? If I really want to test for my own prime, am I able to do so? In such case, what do I do?
What are the specifications for your PC? If it is 'old' PrimeNet will give it Trial Factoring work by default (you are correct that TF can not find a prime, but can find a factor, proving it is not prime.) If you chose 87471793 to test all the way to the end (the LL test), Prime95 will first run some TF and a P-1 test as needed. These are a wise investment as they can more rapidly remove a number of exponents that have factors.

If you just want to run LL tests on number that PrimeNet will assign, open the program. Then from the menu select Test > Worker Windows. In options for "Type of work to get", select "First time tests".

 2013-06-20, 09:22 #4 Unregistered   3·379 Posts Thanks! If i choose "world record numbers to test" or "100.000.000 digit numbers test", how long time will my computer use for this _if_ the number is a prime? If i choose "first time tests", will my computer test numbers that are smaller than the current world record? Are these three options the only one that do "full tests" on "new" numbers? Funny/interesting, this...
 2013-06-20, 11:35 #5 Unregistered   672 Posts Now, I chose "world record tests" in the "worker windows"-menu-option in Prime95. But as a trial factor test finished, i didnt get a new assignment... i know the scheduled assignment have to finish, but the communication thread did not show that i got a new... is this a bug? im using the latest software on windows7. I also tried setting the work to "world record testing" at www, under account type, but then, as three trial factor tests ended, i only got more trial factoring assignment from the server (in the communication thread)...
 2013-06-20, 14:46 #6 Unregistered   1,237 Posts Hi. I'm sorry for the trouble, because now it works. I got LL-assignment. I think it will begin as soon as the previous scheduled TF-assignments are done! :-) Thanks. PS: For the future, if I must uninstall Prime95 and restart, is it best to set the work type in www? It seems that it will get TF-assignments automatically at start-up...
2013-06-21, 00:05   #7
Uncwilly
6809 > 6502

"""""""""""""""""""
Aug 2003
101×103 Posts

290F16 Posts

Quote:
 Originally Posted by Unregistered If i choose "world record numbers to test" or "100.000.000 digit numbers test", how long time will my computer use for this _if_ the number is a prime? If i choose "first time tests", will my computer test numbers that are smaller than the current world record? Are these three options the only one that do "full tests" on "new" numbers?
Doing a LL test takes the same amount of time if a number is prime or not (it has to go all the way to the end to find out the results).
How long it take depends on your computer a lot. Most likely it will take about a year.

Right now there are about 32,000 numbers that will be handed out as "first time tests" that are smaller than the record (that was found this year).

Yes these are the options for "new" numbers.
Quote:
 Originally Posted by Unregistered Now, I chose "world record tests" in the "worker windows"-menu-option in Prime95. But as a trial factor test finished, i didnt get a new assignment... i know the scheduled assignment have to finish, but the communication thread did not show that i got a new... is this a bug? im using the latest software on windows7. I also tried setting the work to "world record testing" at www, under account type, but then, as three trial factor tests ended, i only got more trial factoring assignment from the server (in the communication thread)...
The settings on the machine are primary, if I recall correctly.
What type of processor, speed, and memory do you have?

Quote:
 Originally Posted by Unregistered PS: For the future, if I must uninstall Prime95 and restart, is it best to set the work type in www? It seems that it will get TF-assignments automatically at start-up...
Set it on the machine. If PrimeNet is giving you TF when you have "What ever makes sense" set on the machine, that means you have an older or slower machine. It may take more than a year and a half for a 100,000,000 digit number and more than 6 weeks for a record number.

 2013-06-21, 00:15 #8 TheMawn     May 2013 East. Always East. 11×157 Posts Welcome! Welcome to GIMPS! I hope you stick around. A huge number of people never finish their first assignment when they see how long it takes. Setting up your automatic assignments online is probably a good idea though doing it through the program is fine too. Prime95.exe will regenerate any missing .txt files that it needs so you can erase everything except the .exe and it will start over from scratch and you can change your settings. You can also do that through the menus in the program itself. See Test > Worker Windows. The Primenet server tries to balance out its workload according to what needs to be done. Trial Factoring spends a small amount of time on each exponent testing small prime factors to see if the exponent can be cleared early. P-1 factoring is a different kind of factoring done once trial factoring is finished. After P-1, the actual, direct as you called it, Lucas Lehmer test begins. P-1 is barely keeping up with the LL tests so some times the server will assign P-1 to anyone taking "Whatever makes sense". "Whatever Makes Sense" is the best way to help make sure the server workload is balanced. The amount of time your computer will take to test the numbers is highly dependent on your hardware. What is your CPU? First time tests are done on any exponent which is ready for LL tests but has not had one done yet. Double check tests are another LL test done on an exponent which came up composite once. This is to check that the calculations were done without errors. World record tests are like first time tests but you are specifically asking for numbers which are LARGER than the current world record. GIMPS isn't just trying to find the biggest ones. It's trying to test them all. 100,000,000 digit tests are special because there is a huge prize for finding a prime number with one hundred million digits. It's $150,000 of which$50,000 will go to you if you find it through GIMPS. These tests take a LONG, LONG time to run. It might take you over a year.
2013-06-21, 01:20   #9
Unregistered

25·33·7 Posts

Quote:
 Originally Posted by Uncwilly Doing a LL test takes the same amount of time if a number is prime or not (it has to go all the way to the end to find out the results). How long it take depends on your computer a lot. Most likely it will take about a year.
Ah, I see. But I don't understand it. If a number is a composite, then you find that out be finding the smallest divisor. If it's a prime, you have to test all the possible divisors? Or is the LL-algorithm different from this?

Quote:
 Originally Posted by Uncwilly What type of processor, speed, and memory do you have?
i5-2500 @ 3.3 GHz. My computer have 16 GB RAM, but I assigned only 1. Perhaps it will run faster if i increase? I don't use the machine for awything else, actually.

Quote:
 Originally Posted by Uncwilly Set it on the machine. If PrimeNet is giving you TF when you have "What ever makes sense" set on the machine, that means you have an older or slower machine. It may take more than a year and a half for a 100,000,000 digit number and more than 6 weeks for a record number.
Thats weird, I didnt think my machine was old or slow in this context. Yeah, about 3 weeks according to the schedule to complete LL on a world record number. But the TF did go much faster than what the schedule said.

Quote:
 Originally Posted by TheMawn Welcome to GIMPS! I hope you stick around. A huge number of people never finish their first assignment when they see how long it takes.
Thanks!

The Prime95 says that the chance of finding a world record prime, running 4 threads, were about 1:115,000. And also that it will take about 3 weeks to complete this.

It seems unvalid to me, but if it actually is true, then the chances are better than in the "lottery" that we have here, which are about 1:5,000,000. Hehe.

Quote:
 Originally Posted by TheMawn The amount of time your computer will take to test the numbers is highly dependent on your hardware. What is your CPU?
i5-2500 @ 3,30 GHz.

2013-06-21, 09:43   #10
LaurV
Romulan Interpreter

"name field"
Jun 2011
Thailand

7×1,423 Posts

Quote:
 Originally Posted by Unregistered Ah, I see. But I don't understand it. If a number is a composite, then you find that out be finding the smallest divisor. If it's a prime, you have to test all the possible divisors? Or is the LL-algorithm different from this?
That method you describe is far too inefficient. LL test is a more efficient method. Comparing the "school method" you describe, with LL test, is even worse then comparing a snail with a supersonic airplane. We are talking about the same speed proportion, except that in the case of LL versus "school method", you have to add few thousand zeroes at the end of the speed number, in the favor of LL tests...

More details here.

LL tests will *not* run faster if you assign more memory to them. 1GB is plenty enough. The only work type which is affected by the memory amount is the "stage 2 of P-1/ECM", which you don't normally do if you do "first tests" or "world records", etc. Even for that, not the speed is affected, but the chance to find a factor (i.e. more memory increases the chance).

Last fiddled with by LaurV on 2013-06-21 at 09:51

2013-06-21, 10:18   #11
MacMagnus

Jun 2013

2×3 Posts

Hi, I am "Unregistered" (now registered).

Quote:
 Originally Posted by LaurV That method you describe is far too inefficient. LL test is a more efficient method. Comparing the "school method" you describe, with LL test, is even worse then comparing a snail with a supersonic airplane. We are talking about the same speed proportion, except that in the case of LL versus "school method", you have to add few thousand zeroes at the end of the speed number, in the favor of LL tests... More details here.
Hehe, ok. I knew that it was fast, I just forgot that there are several ways to attack finding primes.

Quote:
 Originally Posted by LaurV LL tests will *not* run faster if you assign more memory to them. 1GB is plenty enough. The only work type which is affected by the memory amount is the "stage 2 of P-1/ECM", which you don't normally do if you do "first tests" or "world records", etc. Even for that, not the speed is affected, but the chance to find a factor (i.e. more memory increases the chance).
Ok, then I leave it at 1 GB. :)

Thanks.

All times are UTC. The time now is 21:53.

Tue May 17 21:53:59 UTC 2022 up 33 days, 19:55, 0 users, load averages: 1.62, 1.51, 1.47