GPU to 72 status... - Page 160

Prime95 · 2013-01-25, 14:45

Quote:

Originally Posted by ckdo

Since my CPU does in fact do DCs faster than my GPU (yes, I did benchmark that), I consider myself part of the "my card can not do DCLL" team. How far should I be factoring?

This logic is flawed, you are comparing apples to oranges. Look at it this way, you say your GPU is not suited to DCLL, but by your logic if you moved your GPU to an old Pentium 4 box the same GPU is now well suited to DCLL.

What LaurV and I recommend is comparing a GPU's TF throughput to a GPU's CUDALucas throughput, one can determine whether a GPU should be doing more TF on an exponent or should run LL on the exponent (or let someone else run the LL).

Uncwilly · 2013-01-25, 17:22

Quote:

Originally Posted by Prime95

What LaurV and I recommend is comparing a GPU's TF throughput to a GPU's CUDALucas throughput, one can determine whether a GPU should be doing more TF on an exponent or should run LL on the exponent (or let someone else run the LL).

Do this, go to James H's page: http://www.mersenne.ca/cudalucas.php
Click on your card. The table that pops up will tell you where the break point is. The green-yellow semi-diagonal line is the break even for DC GPU-LL vs GPU-TF for that card.

Prime95 · 2013-01-25, 20:22

Quote:

Originally Posted by Uncwilly

Do this, go to James H's page: http://www.mersenne.ca/cudalucas.php
Click on your card. The table that pops up will tell you where the break point is. The green-yellow semi-diagonal line is the break even for DC GPU-LL vs GPU-TF for that card.

As noted earlier, this chart assumes no P-1 has been done. It would be great if James could change the chart to show the DC breakeven point when P-1 has been performed (the factoring chart LaurV pointed to, http://www.gpu72.com/reports/factoring_cost/, gives enough information to produce a fairly accurate adjustment to the chance of finding a factor). For extra credit, the web page could offer a checkbox to show the crossover points assuming no P-1 done. Such a chart would help end the speculation as to where we should increase GPU72's DC TF bit depth.

henryzz · 2013-01-25, 23:09

Adding to the confusion doesn't James' page still rely on data from mfaktc 1.19 not 1.20. Isn't the new version quite a bit more efficient as it allows the cpu to be used for DC/LL.

chalsall · 2013-01-26, 00:13

Quote:

Originally Posted by Prime95

Such a chart would help end the speculation as to where we should increase GPU72's DC TF bit depth.

OK... I've finally got myself a semi-reasonable GPU (EVGA GTX 560 2GB "Factory Overclocked") to replace my pathetic FX 1800. Wow! ($600 BDS; $300 US -- not the best and overpriced, but it was the best 2G card available here in Bimshire and I wanted to buy locally to avoid shipping hassles etc.)

The purchase was motivated by my computer vision work, but I'm going to run a few hundred TF runs immediately in front of the wave front in 31M to 70 so we can get a reasonable idea as to what type of percentage we might expect. (31M to 70 has only had 83 attempts before, with zero factors found, so we don't actually have any useful data on what we might expect exactly there.)

The card is only doing one every 25 minutes, so I won't be able to keep ahead of the wave, but I'll do what I can.

Anyone else interested?

swl551 · 2013-01-26, 00:15

Quote:

Originally Posted by chalsall

OK... I've finally got myself a semi-reasonable GPU (EVGA GT560 2GB "Factor Overclocked") to replace my pathetic 1800. Wow! ($600 BDS; $300 US -- not the best and overpriced, but it was the best thing available here in Bimshire and I wanted to buy locally to avoid shipping hassles etc.)

The purchase was motivated by my computer vision work, but I'm going to run a few hundred TF runs immediately in front of the wave front in 31M to 70 so we can get a reasonable idea as to what type of percentage we might expect. (31M to 70 has only had 83 attempts before, with zero factors found, so we don't actually have any useful data on what we might expect exactly there.)

The card is only doing one every 25 minutes, so I won't be able to keep ahead of the wave, but I'll do what I can.

Anyone else interested?

Yes me! Tell me what to do.

chalsall · 2013-01-26, 00:22

Quote:

Originally Posted by swl551

Yes me! Tell me what to do.

Cool. OK. Give me a bit of time (I just got back from the office and we haven't had dinner yet). I need to modify the Assignment form, then bring in some more candidates.

kracker · 2013-01-26, 00:35

Quote:

Originally Posted by chalsall

OK... I've finally got myself a semi-reasonable GPU (EVGA GT560 2GB "Factor Overclocked") to replace my pathetic 1800. Wow! ($600 BDS; $300 US -- not the best and overpriced, but it was the best 2G card available here in Bimshire and I wanted to buy locally to avoid shipping hassles etc.)

The purchase was motivated by my computer vision work, but I'm going to run a few hundred TF runs immediately in front of the wave front in 31M to 70 so we can get a reasonable idea as to what type of percentage we might expect. (31M to 70 has only had 83 attempts before, with zero factors found, so we don't actually have any useful data on what we might expect exactly there.)

The card is only doing one every 25 minutes, so I won't be able to keep ahead of the wave, but I'll do what I can.

Anyone else interested?

Sure! Although my firepower sucks, Count me in

Prime95 · 2013-01-26, 00:38

Quote:

Originally Posted by chalsall

... I'm going to run a few hundred TF runs immediately in front of the wave front in 31M to 70 so we can get a reasonable idea as to what type of percentage we might expect. (31M to 70 has only had 83 attempts before, with zero factors found, so we don't actually have any useful data on what we might expect exactly there.)

I have no reason to believe the hit rate would be any different than in the 32M range -- and we have a lot of data there.

chalsall · 2013-01-26, 00:51

Quote:

Originally Posted by Prime95

I have no reason to believe the hit rate would be any different than in the 32M range -- and we have a lot of data there.

I agree. Also in the 30M range. And the average between the two is 1.1546% -- better than the ~1% suggested.

davieddy · 2013-01-26, 00:54

At the risk ud getting my head bitten off again, may I remind you all that if it's worth TFing 30M to 71, then it's worthi taking 60M to 75.

David

2013-01-26, 00:54	#1760
davieddy "Lucan" Dec 2006 England 2×3×13×83 Posts	TF level At the risk ud getting my head bitten off again, may I remind you all that if it's worth TFing 30M to 71, then it's worthi taking 60M to 75. David

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2013-01-25, 23:09	#1753
henryzz Just call me Henry "David" Sep 2007 Cambridge (GMT/BST) 13377₈ Posts	Adding to the confusion doesn't James' page still rely on data from mfaktc 1.19 not 1.20. Isn't the new version quite a bit more efficient as it allows the cpu to be used for DC/LL.