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-   -   Quick Question about assignments (https://www.mersenneforum.org/showthread.php?t=16104)

davieddy 2011-10-20 01:43

[QUOTE=Dubslow;275136]Really? News to me.[/QUOTE]
Everyone (including you) who mentioned a bit level in this
thread said 72.
Two huge threads in the lounge discuss this. 72 is what is
feasible (and comfoortably so) if the assignment was simpler
and organized as I suggested:
Let a larger number of folk each grab fewer expos and take them
to 72 in one go for expos AT, not 2 years AHEAD of, the wavefront.

David

davieddy 2011-10-20 02:05

[QUOTE=Mr. P-1;275082]Option 1: TF 25 newly-expired assignments from 68 to 72, and find about 1 factor that would not otherwise be found (assuming a 1% chance of finding such a factor per bit level).

Option 2: Using the same resources, TF 375 newly-expired assignments from 68 to 69. amd find about 3.75 new factors.

Otherwise, the most likely outcome is that the expiries will be re-taken up for LLing and never TFed further.[/QUOTE]
[QUOTE=garo;275113]Bingo![/QUOTE]
[QUOTE=Mr. P-1;275129]Would it be better to give you batches of 2,250 (grabbed over several days of course) to take up to 69 only?
[/QUOTE]
[SIZE=7][COLOR=red]NO [/COLOR][/SIZE]
the most likely outcome is that the expiries will be re-taken up for LLing and never TFed further than 69.


[COLOR=seagreen][/COLOR]

davieddy 2011-10-20 03:09

Please read thoughtfully
 
[QUOTE=Mr. P-1;275120]If we have 15 GPUs each capable of doing 25 exponents from 68 to 72, then we could do that, and discover 25 new factors. Or we could TF 5,625 exponents from 68 to 69, and discover 88 new factors, assuming that 5,625 exponents TFed to 68 are available

The relevant questions are: How many GPUs do we have available for this work? How many exponents are they capable of processing in a day from 68 to 69? To 70? To 71? To 72? How many LL exponents expire each day? How many are assigned each day? Do we have enough GPU power available to bring one full day's worth of LL assignments up to 72 every day? If not, how high could we get one full day's worth of LL assignments up to every day?
[/QUOTE]
[URL]http://www.mersenne.info/trial_factored_tabular_delta_180/2/50000000/[/URL]

From ~53.5M to 61M, 130,000 have been TFed 2 more bits in the last
six months. The wave front has advanced by 1.5M which means
~30,000 "status unknown" exponents.
We could have TFed all these 30,000 to 72 bits, with enough to
spare to TF the entire "tail" < 53.5M by 2 or 3 extra bits.

WHY THE HELL HAVEN'T WE?

Because we adopted option 2 up to 61M which won't get assigned
for another two years "to keep the GPUs busy", and find your oh so precious low-hanging fruit factors.

David

Christenson 2011-10-20 03:46

Davieddy:
Please remember that GIMPS is like herding cats...and I can only control what I do, not what the big firepower does. I'm not too worried about a 10% or so (assuming we find lots of factors) loss of efficiency on LL testing in the short term.

Also, if we can have GIMPs hand out its last 68-bit TF'ed assignment next week, we will be much further ahead than if it hands out 15 68 bit TF'ed assignments noone has been able to bring up to 69 bits because they were all trying to bring the current exponents to 72 bits. But I'm not going to complain about *any* TF activity in the middle of the LL assignment wavefront. Every factor found saves LL tests, and that's what it's about. Each additional bit level is twice as hard as the last, and in a resource-limited context, doing the easy ones first is most effective.

If you want more productivity, I need a way to restart crashed Windows machines from afar, and about a grand (US$1000) to put together a screamer TF/P-1 machine with a GT580 GPU, a 1KW power supply, and a hot CPU. A UPS wouldn't hurt either, as small power glitches are hard on my high-powered machines. And I need a little less pressure at work, so I get home and work on mfaktc....the primenet side.

Dubslow 2011-10-20 04:56

[QUOTE=Mr. P-1;275141]The two people don't need to get on at the same time. The current owner can unreserve, log out, then manually re-reserve seconds later. I pretty certain that, with knowledge of the keys, "anonymous" assignments can be claimed.[/QUOTE]

Ah. I'm willing to give it a shot. Let me know when you've done it, and you'd need to send me the new keys. Can anybody else confirm or deny this? (Please reserve the LL's as LL's, not P-1)

Mr. P-1 2011-10-20 11:24

[QUOTE=Christenson;275147]Who is the right person to check with on the reservation system? P95?[/QUOTE]

I guess so.

[QUOTE]And do you have any scripts (Linux64) to assist with manipulating assignments?[/QUOTE]

I have scripts to convert Test= assignments to Pfactor=, to make a 2-core worktodo file from an undifferentiated list of assignments, and to convert Test= and Pfactor= assigments to Factor= assignments. I find I can generally whip up a script to do whatever I want in a few minutes. I'm sure you could do the same.

[QUOTE]While I'm at it, what happens if I put an assignment key on my "no factor found" lines on the manual results page?[/QUOTE]

Nothing, I would guess.

I asked both Dubslow and you to unreserve the exponents I gave you when you were finished with them, but this was based upon the assumption that with the keys, you would be able to do this. Since that assumption appears to have been mistaken, I think the easiest thing to do would be for both of you (and garo) to just PM when you're done with them, and I'll unreserve them.

In future, if I'm grabbing on behalf of others, I'll try to make sure I'm logged out at the time, so they won't be assigned to me.

Mr. P-1 2011-10-20 11:47

[QUOTE=Dubslow;275158]Ah. I'm willing to give it a shot. Let me know when you've done it, and you'd need to send me the new keys. Can anybody else confirm or deny this? (Please reserve the LL's as LL's, not P-1)[/QUOTE]

This is weird. Of the five exponents I gave you for LL, only 2 are still assigned to me. The other 3 have been reassigned to "ANONYMOUS". Possibilities are 1. I screwed up again somehow. 2. You managed to unreserve them somehow and someone else has them now. 3. You managed to rereserve them somehow. 4. Something else.

I'm not sure, but for now I'm filing this whole "give keys assigned to me to someone else" business in the box marked "unpredicable results", and I don't propose to do it again.

I'll try to do the "unreserve then rereserve anonymously" trick on the two exponents I still have, and on three others. You'll get your five LL exponents, but not necessarily the same ones.

As for the rest, the ones you're just going to TF, I'll check to see if I still have them reserved. If so, I'll just keep them and unreserve them myself when you're done. Expect a PM shortly.

Mr. P-1 2011-10-20 12:21

[QUOTE=Mr. P-1;275168]Expect a PM shortly.[/QUOTE]

Or not. The server is somewhat unresponsive just now, and I'm having difficulty in getting any manual assignments at all. I'll try again later.

Mr. P-1 2011-10-20 13:04

[QUOTE=davieddy;275152]WHY THE HELL HAVEN'T WE?

Because we adopted option 2 up to 61M which won't get assigned
for another two years "to keep the GPUs busy", and find your oh so precious low-hanging fruit factors.[/QUOTE]

David, we're not talking about those other GPUs which are working in the 61M range, as we have no control over what those GPUS do. We're talking about the GPUs of the people in this thread who have them, and who have expressed an interest in working in the sub 50M range. These people do not appear to include you. The question before us is how [i]we[/i] can optimize [i]our[/i] contribution to GIMPS, not how to fix GIMPS' TF assignment system generally. And of course, by "we" I mean "they". I don't have a GPU either, though I intend to get one within the next few months.

My current best guess is that these people - Dubslow, Christenson, and garo - together have the capacity to TF every 68-bit expiry every day to 70 bits with room to spare, assuming they do nothing else with their GPUs. The question is: what to do with that room to spare. My proposal: use it to factor as many 69-bit expiries to 70 bits as we can, giving priority to those 69-bit assignments which have not had a P-1.

Your proposal appears to be that we TF a smaller number of sub-50M exponents to 72 bits every day, leaving the rest to other people to TF. The problem with this idea is that [i]there don't appear to be any other people TFing in this range[/i]. Instead of being TFed to 72 bits, these other exponents will be left at 68 or 69 bits. Moreover, every exponent we take to 72 bits instead of 70 means six other sub-50M exponents left at 69 bits or twelve at 68 which could otherwise have taken to 70. How is this better?

We could also try to recruit more GPU owners to the effort. With enough, we could maybe take all expiries to 70 bits and then some to 71. Perhaps one of us should post a call for assistance in the GPU forum. However before we do that, I think we need to sort out a system for coordinated assignment "grabbing" and distribution. To get every 68 bit expiry, we will need to "grab" every day. I've volunteered to do some "grabbing", but I'm not sure I want to commit to doing it every day.

Oh, and another thing: Whoever posts the call for assistance, please let it not be you. So far, all you've achieved is to piss everyone off on the subject.

Mr. P-1 2011-10-20 13:32

[QUOTE=Mr. P-1;275175]My current best guess is that these people - Dubslow, Christenson, and garo - together have the capacity to TF every 68-bit expiry every day to 70 bits with room to spare, assuming they do nothing else with their GPUs.[/QUOTE]

Could the three of you each give an estimate of just how many exponents you could TF from 68 to 70 bits in a day? I'd like a better figure than my "best" WAG.

garo 2011-10-20 21:01

I've got a script set up to run tonight that will grab some small LL tests at 0000 UTC. My guess is that it will only get about 6 exponents so you can keep grabbing exponents as and when you can. I'm not sure how long trial factoring a 45M to 70 bits takes on my GPU. My guess is 40 minutes so I could do about 35 of these exponents in a day. I'll have more precise numbers this weekend.

At this point in the discussion, if davieddy continues to refuse to distinguish between TFing of 55-60M and TFing of 42-50M the best we can do is ignore him.


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