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Old 2020-01-12, 22:48   #12
petrw1
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Quote:
Originally Posted by masser View Post
No. My guess is that the low ram instance did not do the Brent-Sumaya extension; I've noticed that I get a little more credit with the E=12 results.
Could be; in the 41.8M ranges there are 3 PCs.
The PC getting the lowest credit (3.2622) with the least RAM is always E=6
The other two are getting 3.3783; with more RAM and always E=12
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Old 2020-01-12, 23:34   #13
kriesel
 
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Originally Posted by petrw1 View Post
Yes, I understand and do that....

By the way, for some reason I am doing reasonably better than this.
For the last 2 years I have been re-doing P-1 in 40M-59M where B1=B2.
That people are doing those B1=B2 in the first place is very unfortunate. It doesn't yield enough factors to pay for the work of doing that, and then doing the full-bounds P-1 repeats that work plus performs some more.
Quote:
My question, though, is how can I calculate the expected TF success rate where a little or a lot of P1/ECM has been done?
The difference method should work there too. Two cases at the mersenne.ca calculator, same B1,B2, different tf levels.
Quote:
So if I am TF'ing at somewhere in the 72 to 75 bit ranges I should expect a success rate of about 1.35%.
But again with a large sample size (about 50,000) my average is consistently very, very close to 1%.
All of these TF runs are for exponents that have had some P1 done.
The exponents that are remaining unfactored after the P-1 had no p-1-smooth factors to the P-1 bounds used, which is likely above the TF levels to be run. That leaves fewer factors to find with TF. As I recall estimates were 20-25%. 25% of 1.35% is ~0.34, a pretty good match to what you're seeing.
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