[QUOTE=Prime95;264790]GIMPS would be better served by moving much of the TF firepower over to LL testing. Since I can't do that...[/QUOTE]

Why not? How about temporarily eliminating/limiting TF (below 100M) as an available worktype, and handing out DCs or LLs (or if we must, for those who really, really want to TF, TF-LMH assignments) instead?

[QUOTE=NBtarheel_33;264839]Why not? How about temporarily eliminating/limiting TF (below 100M) as an available worktype, and handing out DCs or LLs (or if we must, for those who really, really want to TF, TF-LMH assignments) instead?[/QUOTE]

"Find out what little Johnnie is doing and tell him to stop it".
(He is using his GPU to do what it does best ATM).

There are two different motives for TF.
One is to find factors as frequently as possible.
The other is slightly more subtle: eliminate the necessity for two LL tests,
(in a few cases) and enhance the chance of the rest being prime.

The latter is what we are discussing, and may be viewed as a thankless
task: little reward (factors) for much* time. I have assured Christenson that if the number I am currently testing turns out to be prime, I shall
publicly acknowledge his TFing 6 more levels, thereby ensuring my "effort"
was worthwhile, and donate an appropriate number of $ should I win any!

* "much" here means about a day on his GPU, which has to be compared
with 2 months for the LLtest on my CPU.
There was a 9% chance of him finding a factor, thereby
sparing me a futile LLtest.

David

Deleting thoughts
 

[QUOTE=davieddy;264827]
The "baby" you flushed down the toilet....[/QUOTE]

Another one was this:
Look at the size of the typical factor found via P-1 compared with
the TF max to judge how little the two enterprizes overlap each other.

David

[QUOTE=NBtarheel_33;264839]Why not? How about temporarily eliminating/limiting TF (below 100M) as an available worktype, and handing out DCs or LLs (or if we must, for those who really, really want to TF, TF-LMH assignments) instead?[/QUOTE]

That would be fine, but right now, the firepower, as a group, and this includes myself, goes to the "manual assignments" page, and says: Gimme a TF assignment (or a hundred or three)...and then proceeds to TF it in a jiffy with a hot GPU. It will get a bit worse when mfaktc is upgraded to automatic mode, as the program will do this for us on automatic, so very little neurological bandwidth will be required. Thus it is I suggest P95 increase the TF bit levels, even on exponents that have already received a first LL.

There isn't a way to say "Give me the assignment that makes the most sense for GIMPS"...there is no CUDA P-1 program, and I don't have the CUDA LL program installed....although maybe I should. Thus it is I encourage DavieDDy to make that task easier.

P-1 on my CPUs has actually been significantly more productive in eliminating LL candidates than running LL tests.

[QUOTE=Uncwilly;264810]Yes indeed. There are 91 days left until we match the longest gap in the GIMPS era. And 114 days from hitting the average gap + 2 std dev.
10metreh has our next closest (non-expired) guess, 59,278,411 on 6/30/2011
And: makes the guesses look like a bad bet:
tom11784.....38,066,453 [strike]6/23/2007[/strike]
T.Rex...........38,500,000
PrimeCrazzy..39,999,999 [strike]9/1/2007[/strike]
wpolly..........41,991,811 [strike]4/19/2008[/strike]
lycorn..........41,999,999 [strike]11/30/2007[/strike]
Andi47.........42,000,000 [strike]8/1/2007[/strike]
edorajh........42,500,000 [strike]10/1/2009[/strike][/QUOTE]

Have you googled "Gambler's Phallusy" yet?

If so, why do you persist with this puerile poop?

Tried to get the "smily" but it was taking forever for the
page to come up. Laxative required.
I bet you are partly to blame.

David

[QUOTE=davieddy;264842]Another one was this:
Look at the size of the typical factor found via P-1 compared with
the TF max to judge how little the two enterprizes overlap each other.

David[/QUOTE]

And you somehow think that this is a mathematical argument???

All you have done is gainsay the mathematics that I have presented,
claiming that my arguments were "pulled from my ass" or "bull".
What a mature way to conduct a technical discussion.

Did it ever occur to you that P-1 is generally a better algorithm?
That it is expected to find larger factors on average? Do you
understand why?


Did it occur to you that TF is usually done first, and its factors
are bounded in size? Try running P-1 [b]first[/b] and you will find that
many/most of the factors found by TF will now be found by P-1.
You will also find that the variance of the size of factors found by
P-1 will increase.

I am suggesting that you can SAVE TIME by NOT running TF at all;
Just run P-1 with slightly higher bounds that are currently used.

[QUOTE=Prime95;264828]You are correct in the characterization of your previous posts. I overstepped in my description of your deleted posts (some by me, some by another moderator). Nevertheless, these posts seem needlessly incendiary considering the past tensions between the two of you.

The moderators are merely trying to nip any flame wars in the bud. They were annoying to the combatants, the readers, and the moderators. Thanks for cooperating.[/QUOTE]

He also failed to discuss any mathematics! All he did was claim that
my arguments were bull; a reflection of his mathematical ignorance.

Claiming that a 2 yr old would see that my arguments were wrong
without bothering to even discuss the mathematics [b]IS[/b] a form
of derision.

[QUOTE=Christenson;264843]
P-1 on my CPUs has actually been significantly more productive in eliminating LL candidates than running LL tests.[/QUOTE]

Why is that?

David

[QUOTE=R.D. Silverman;264849]He also failed to discuss any mathematics! All he did was claim that
my arguments were bull; a reflection of his mathematical ignorance.

Claiming that a 2 yr old would see that my arguments were wrong
without bothering to even discuss the mathematics [B]IS[/B] a form
of derision.[/QUOTE]

Touche

[QUOTE=R.D. Silverman;264848]And you somehow think that this is a mathematical argument???
[/QUOTE]

Did you ever try to teach your grandmother how to suck eggs?

[url=http://www.youtube.com/watch?v=kQFKtI6gn9Y] I paid for a mathematical argument[/url]

No you didn't

[QUOTE=R.D. Silverman;264848]I am suggesting that you can SAVE TIME by NOT running TF at all; Just run P-1 with slightly higher bounds that are currently used.[/QUOTE]

Getting this thread back to the math/optimization problem....

P-1 and LL tests are done on the same caliber of Intel/AMD machine. The P-1 bounds are selected comparing the time it takes to run P-1 to the cost of running 2 LL tests times the chance of P-1 finding a factor. Barring any bugs in my understanding of P-1's chance of finding a factor or in my programming, increasing P-1 bounds would be a bad idea because that extra P-1 time would remove more candidates if it were used for LL testing instead.

The "problem" GIMPS faces is we now have GPUs which are 100x faster at TF than the Intel/AMD machines. What is the best use for this resource?

I've been using them to do more TF on LL candidates. A recent run of one extra TF bit level on 9000 exponents that had already had P-1 done found factors in 1 out of 105 cases instead of the usual 1 out of 70 cases. Thus, the extra TF effort is of some significant value -- in essence making GIMPS' LL resource more effective.

When extra TF is done before P-1 has been performed, the extra TF reduces the P-1 bounds (because the chance of finding a factor is reduced). Thus the extra TF lets GIMPS' P-1 resource test more candidates.

I can see merit to your argument that we should do more P-1 rather than more TF, but the GPUs are only 100x faster at TF. IIRC, they are 4x faster at LL. GPUs cannot do P-1, but if they could they'd also be only 4x faster (or less).