Quote:
Originally Posted by paulunderwood

The records in CHG are not in the size but the % factored part, and I've played with that some years earlier.
Among other things, I have proven a relatively uninteresting, artificially constructed (around 25.2% factorization of
10^732601)
75k digit prime with CHG back in '11. It took literally weeks. I don't think I reported it, because I got bored and delayed the Prime proof of the dependent p8641. I finished it some time later when I could run a 32thread linux Primo (in FactorDB, it is also proven by Ray C.).
Code:
n=10^7551610^22561;
F=1;
G= 27457137299220528239776088787.....00000000000000;
Input file is: TestSuite/P75k2.in
Certificate file is: TestSuite/P75k2.out
Found values of n, F and G.
Number to be tested has 75516 digits.
Modulus has 20151 digits.
Modulus is 26.683667905153090234% of n.
NOTICE: This program assumes that n has passed
a BLS PRPtest with n, F, and G as given. If
not, then any results will be invalid!
Square test passed for G >> F. Using modified right endpoint.
Search for factors congruent to 1.
Running CHG with h = 16, u = 7. Right endpoint has 15065 digits.
Done! Time elapsed: 35477157ms. (that's ~10 hours for one iteration)
Running CHG with h = 16, u = 7. Right endpoint has 14861 digits.
Done! Time elapsed: 151834429ms. (that's ~42 hours! for one iteration)
Running CHG with h = 15, u = 6. Right endpoint has 14651 digits.
Done! Time elapsed: 11931826ms.
...etc (43 steps)
Two things happened over three years: the computers got better, and Pari was made better! (and GMP that Pari uses can and probably uses AVX these days).
I was pleasantly surprised how fast the 388k prime (but of course 29.08%factored) turned out to be. And just three iterations, too.