My Apologies

[Rodrigo]

Originally Posted by chalsall

If you *must* bring these slow machines online, simply select "TF-LMH" on the client during Prime95 installation, and let the server assign work to you. It is not worth your time learning how to "self-assign" when all <64 bit TF work above 200M will be completed in about a week.

(For example, the 932-933M, 934-935M, 936-937M, 938-939M ranges are already long gone....)

chalsall,

Thanks for the tip, and for the update on the available ranges. I'll keep things on the simpler side, at least while I'm getting acquainted with the whole process.

Do I remember it right that it's recommended to go into the LMH section to reserve work? I'm guessing that one would do that in addition to (rather than instead of) having the server assign the work.

Rodrigo

[Rodrigo]

Originally Posted by axn

Wow, indeed. Currently, the lowest open prize is for 100million (exponent>333M) digit prime. The fastest quad-cores will take nearly a year to complete a single test, running on all four cores!!! (see this thread for benchmarks: http://www.mersenneforum.org/showthread.php?t=13185)

axn,

I'll check out that link right away, thank you!

Rodrigo <trying to learn fast>

[mdettweiler]

Originally Posted by Rodrigo

chalsall,

Thanks for the tip, and for the update on the available ranges. I'll keep things on the simpler side, at least while I'm getting acquainted with the whole process.

Do I remember it right that it's recommended to go into the LMH section to reserve work? I'm guessing that one would do that in addition to (rather than instead of) having the server assign the work.

Rodrigo

If you have PrimeNet automatically assign you LMH work, then there's no need to reserve the work in the forum; that's all handled automatically by the server. The only times you need to reserve it in the forum is when you want to take a large range that you selected yourself (rather than the server selecting the exponents for you) and thus need to make sure nobody else doing the same thing "steps on" your range. The independent LMH workers stay clear of the server's work areas on their own, so anything you get from it is all clear.

[Rodrigo]

Originally Posted by mdettweiler

If you have PrimeNet automatically assign you LMH work, then there's no need to reserve the work in the forum; that's all handled automatically by the server. The only times you need to reserve it in the forum is when you want to take a large range that you selected yourself (rather than the server selecting the exponents for you) and thus need to make sure nobody else doing the same thing "steps on" your range. The independent LMH workers stay clear of the server's work areas on their own, so anything you get from it is all clear.

mdettweiler,

Ah, that's very good to know -- thanks!

I've learned so much today; the fog is slowly lifting.

Rodrigo

[Primeinator]

Originally Posted by Rodrigo

Hello,

About a month ago I had posted here seeking information on whether it was possible to set up multiple computers to help each other out. Everybody who answered my rookie questions (http://mersenneforum.org/showthread.php?t=13515) was most helpful and patient.

I want to thank all who took the time to help me figure things out. But more importantly, I want to offer my sincere apologies for leaving everything hanging for these several weeks as we dealt with certain private matters.

But now I am back, hopefully for good, and I'm ready to start my PCs contributing to GIMPS.


Rodrigo

Welcome back, Rodrigo! The advice given above is very sound. I'm did not read all of the posts, but to answer your question posted above- it is possible to select "world-record size first time tests" from the work type menu. These exponents will not qualify for a prize 'until' a 100M digit has been found, then money will be allocated out for all the primes found after the allocation of the previous prize. However, it is important to note two things about this caveat. Firstly, the amount given will likely be small. Second, this could take a long, long time as a 100M digit candidate takes years to test on the average computer. I myself have two computers working for GIMPS; the faster (quad core) is doing first-time tests of world record size while the second will be moved to double checks when it finishes its current assignments. Hope this helps!

Side note: Beautiful, glorious, correct grammar!

[ET_]

In case you find out that your older machines are too slow to get into GIMPS, please consider also donating your CPU cycles to other projects, like (hint! hint!) Operation Billion Digits... We just opened some new ranges at 62 bits (and factoring billion digits Mersenne numbers is faster than 100 million digits).

Luigi

[10metreh]

Originally Posted by ET_

In case you find out that your older machines are too slow to get into GIMPS, please consider also donating your CPU cycles to other projects, like (hint! hint!) Operation Billion Digits... We just opened some new ranges at 62 bits (and factoring billion digits Mersenne numbers is faster than 100 million digits).

Luigi

I agree. I think that the big guns shouldn't do OBD because it is too low-priority. They should do DC instead: that is what is needed ATM.

[Rodrigo]

Primeinator,

Well, thanks for the comments on my grammar! I imagine that most of the folks here are excellent at math. For me, everything up to Probability was interesting and fun, but I knew I wasn't cut out for sophisticated mathematics when the time came to do trigonometry, and then calculus. Doing integrals was enjoyable, but derivatives were just incomprehensible to me (or was it the other way around -- been a long time). And when homework started to consist of determining the volume of cones , I realized that my career was going to involve working with words and not numbers.

Thank you, too, for explaining the world-record tests, I appreciate it. Are those related to the numbers that qualify for the smaller Mersenne Prime Awards (http://www.mersenne.org/legal/#awards)?

One more question, if that's O.K.--

About those smaller, interim awards for finding sub-100M primes: When getting work for your (modern) PCs, would you do anything differently if you were pursuing a Mersenne Prime Award vs. the 100 Million Digit Prime Award? The reason I ask is that I'm thinking that maybe a more modest goal would be in order, but maybe these two functions just go together naturally and there's no need to choose one or the other.

Gratefully,

Rodrigo

[Rodrigo]

Originally Posted by ET_

In case you find out that your older machines are too slow to get into GIMPS, please consider also donating your CPU cycles to other projects, like (hint! hint!) Operation Billion Digits... We just opened some new ranges at 62 bits (and factoring billion digits Mersenne numbers is faster than 100 million digits).

Luigi

Luigi,

Thank you for the suggestion. OBD is definitely in the running. Even if the ultimate goal is that much further away, knowing that my older machines are completing more tasks in a given time is an attractive option.

How would I get OBD work assigned to my PCs?

Rodrigo

[mdettweiler]

Originally Posted by Rodrigo

About those smaller, interim awards for finding sub-100M primes: When getting work for your (modern) PCs, would you do anything differently if you were pursuing a Mersenne Prime Award vs. the 100 Million Digit Prime Award? The reason I ask is that I'm thinking that maybe a more modest goal would be in order, but maybe these two functions just go together naturally and there's no need to choose one or the other.

The Mersenne Prime Award ($3000) is awarded for the discovery of *any* new Mersenne prime with less than 100 million digits. The "First Time Tests" and "World Record Tests" work options both assign tests within this range. In many cases both would assign the same numbers, though "Workd Record Tests" is specifically limited to numbers above the largest known prime, whereas "First Time Tests" can give out smaller "fill-in" work as available that hasn't yet been completed. Either could just as easily produce a prime eligible for the Mersenne Prime Award. Additionally, the LL-10M choice, which produces first time tests of 10 million digits or greater (left over from the last big award for 10 million digits), nowadays is almost exactly the same as "First Time Tests" because almost all numbers less than 10 million digits have already been tested once. All three options produce numbers that will test in about 3-4 weeks on one core of a modern CPU.

The 100 Million Digit Prime Award ($50000) is awarded for the discovery of the *first* prime of 100 million digits or greater. This means numbers much, much bigger than the current world record and the leading edge of "First Time Tests" progression. You must select the LL-100M choice to get numbers of this size, though they're so big that they'll take over a year to do even with four cores of a modern quad working on the same test. (Only a few weeks ago was the very first of these actually completed.)

So the two goals are in fact mutually exclusive--100 million digit numbers are specifically excluded from the $3000 Mersenne Prime Award because they've already got the $50000 award reserved for them. Note that the 100 million digit numbers, due to their size being so far ahead of today's computer processing capability, have an extremely remote chance of finding a prime any time soon. Even the "normal" first-time LL tests have a rather remote chance of any individual user finding a prime, though at least the chances are enough that GIMPS as a whole has a decent chance of finding one every couple of years.

Even though the potential rewards of working for the 100 million digit prize is much greater, the odds of actually achieving it are infinitesimal. With the Mersenne Prime Award, the dollar amount is comparatively small, but you'd at least have sort of a chance of actually getting it. It's like playing regular lottery vs. Mega Millions--the chances of winning either is remote, but the latter is so much harder that you'd probably have better luck trying to win the smaller lottery multiple times. At GIMPS, the odds against winning the 100 million digit award (i.e., "mega millions") are even more disparate from the Mersenne Prime Award (i.e. "regular lottery") than they would be with a real lottery.

[Rodrigo]

mdettweiler,

Wonderful explanation from beginning to end, thank you -- just the sort of thing I was hoping for! It was a HUGE help.

Rodrigo