mersenneforum.org Can someone explain these P-1 Relative Primes variances?
 Register FAQ Search Today's Posts Mark Forums Read

2020-01-12, 22:48   #12
petrw1
1976 Toyota Corona years forever!

"Wayne"
Nov 2006

26·67 Posts

Quote:
 Originally Posted by masser 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

2020-01-12, 23:34   #13
kriesel

"TF79LL86GIMPS96gpu17"
Mar 2017
US midwest

24·239 Posts

Quote:
 Originally Posted by petrw1 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.

 Similar Threads Thread Thread Starter Forum Replies Last Post wildrabbitt Homework Help 13 2019-09-29 16:23 petrw1 Factoring 4 2018-11-07 20:20 Fred Software 5 2016-04-01 18:15 tha Software 14 2015-10-30 01:23 timbit Information & Answers 0 2009-03-13 18:45

All times are UTC. The time now is 06:14.

Mon Jun 1 06:14:41 UTC 2020 up 68 days, 3:47, 1 user, load averages: 1.14, 1.37, 1.45