Sierp base 6 - team drive #3

[Lennart]

Congrats Max :)


Lennart

[mdettweiler]

Well, this was quite the fun surprise in my mailbox this morning:

31340*6^833096+1 is prime!

My largest yet! (Just under 2 megabits.) When I first saw it I wasn't quite sure if it had topped my personal record - I'd nabbed a prime at n=1.97M a while back on the base-2 multi-conjecture drive, so I thought, 648280 digits is a bit under 2M, probably not quite enough to beat 1.97M. I was, however, glad to see that my intuition was wrong when I reported it!



Another down, 14 to go!

Edit: Okay, now someone else needs to bring one in and make it a pair.

[gd_barnes]

Way to go Max!

[mdettweiler]

Found another big base 6 prime over the Christmas holiday while I wasn't watching my computers so closely...you know what they say, a watched pot never boils (and the converse certainly seems to have been true for the last number of primes I've found!).

125098*6^896696+1 is prime! (697771 digits)
(incidentally, my new personal record by about 50,000 digits)

13 k's left to go...and just 100K more to n=1M!

[gd_barnes]

[MyDogBuster]

That deserves an Atta Max

[mdettweiler]

Looks like I missed this one a couple weeks ago:

33706*6^910462+1 (708482 digits)

12 k's to go!

[gd_barnes]

Originally Posted by mdettweiler

Looks like I missed this one a couple weeks ago:

33706*6^910462+1 (708482 digits)

12 k's to go!

[mdettweiler]

Believe it or not, it looks like we're close to finishing this! (sort of...) By my estimate, we'll be reaching n=1M in about 10 days.

This, of course, exhausts our remaining sieve file for this drive. I believe the intent is to put the base 2/4 k's currently being done in the sieving drive into port 1400 next - Gary, is that correct? I see we're still some distance from the optimal depth of p=650T; I wonder if we might be close enough to break of p=2M-3M, though.

In any event, I'll keep the cores I've got on port 1400 (all but one i5 quad which is on NPLB 2000) for the foreseeable future. During the summer, that will be:
-Core 2 Duo E4500 (2 cores, circa 2007)
-Phenom II X4 N970 (4 cores, laptop circa 2011, actually a little slower than the Core2 for this size of tests due to not much cache)
-i7-2620M (2 cores with HT, laptop circa 2011 - much faster)

Not much, but we've had some others helping out on 1400 lately, so things have been moving much more quickly. Particularly, I see one core each of an Ivy Bridge and a Haswell on there - those carry a lot of weight.

[gd_barnes]

Yes this drive has gone faster than I expected. As for port 1400, unfortunately it will go offline when this drive is finished until we finish sieving the base 2/4 k's to P=650T. The optimal sieve depth is for all of n=2M-5M. Breaking off a portion of that would be long term inefficient.

[gd_barnes]

Another thought: After Sierp base 6 is done here to n=1M, what would everyone think of crunching Riesel base 6 on port 1400 until our new base 2/4 drive is done sieving? R6 currently has 2 k's remaining and is at n=1.5M with no reservations and is sieved thru n=2M. The tests would be ~2-3 times as long as S6 at n=1M but there are < 1/5th as many candidates so the n-ranges would process more quickly. We would not have to test the entire rest of the range thru n=2M in the highly likely event that the base 2/4 effort is done sieving first, although we could ask people what they think at that point.