What is the status of the search and another link

[mdettweiler]

Originally Posted by paulunderwood

I plan to hand over the remaining files to PrimeGrid, if and when we find the next prime. I have already discussed this John in emails between us.

PrimeGrid has two advantages. The first is they double-check results -- larger numbers are more error prone. The second advantage is people can just point their Linux and Windows boxes at the server -- Mac Intel too?

PrimeGrid doesn't have a MacIntel app available yet, though I imagine it will be available in the somewhat near future, considering that a MacIntel build of LLR now exists.

[paulunderwood]

I thought I had better write something about how things are going for the 321search project.

We have no numbers less than 1 million digits left for first time testing.

PrimeGrid have been on board for a couple of months and they have increased the search's throughput greatly.

We have started testing at 4 million bits. The new batch here for manual testing takes much longer, nearly 50% longer, to crunch compared to the previous batch because the new ones are much longer -- PrimeGrid and James Burt are doing the intermediate ones -- and use a bigger FFT window. The effect of worse caching and bus contention must kick in at some length -- whether we are there yet I do not know.

[paulunderwood]

My thanks goes to Xyzzy for uploading and hosting the new batch of input files.

Candidate primes start at n=4.35 million or 1,309,480 decimal digits. There is a new FFT size for this batch, so expect individual tests to take about 20% longer than before.

Good luck!

[paulunderwood]

The plan now for 321search is to continue with PrimeGrid to n=5M. Thereafter PrimeGrid will take over. They are currently sieving to n=10M. I guess there are 2 or 3 more primes below that.

There is a chance we will find another megaprime below n=5M -- I am hoping for some bunching now in the sequence of 321 primes

With PrimeGrid's help we should be able to finish to n=5M within 6 months

[paulunderwood]

PrimeGrid have been running "Drive for Five" for the last week. It will be running until the end of this month. Even if they fail to reach n=5M by then, the time to completing our task will have been greatly shortened -- anything remaining will be mopped up within a month or two

Maybe we will have a bonus prime too

[paulunderwood]

PrimeGrid and many of its members have done a great work to get to 5M. Although there are hundreds of results to come in, they have exhausted their 321 input :surprised

James Burt has a few outstanding ranges below n=4M. Many of them will be put on the PG server soon. I am still hoping all n=sub-5M will be done by the end of June, but my guess is that there will be a few left over to do then.

Unfortunately, no prime has showed up yet

[paulunderwood]

I happy now with the coverage of 321 numbers below n=5M. Before this project is achived, I will create a new thread with all the results, including:

• factors
• llr residues
• primes
• double checks
• errors

[paulunderwood]

A change of plan: I have handed all the 321 factors and LLR results over to PrimeGrid. John says they hope to make a public database in the future.

I would like to thank the following for their help with "321search" over the last few years:

* Thomas Ritschel for his major contributions with sieving, crunching LLR, scripts, encouragement, discussion and ideas.
* The many loyal sievers and LLR crunchers who are listed on this subforum and at The Prime Pages
* PrimeGrid users and its organizers for their huge boost to throughput towards the n=5M goal
* Programmers: Jean and George for LLR; Paul Jobling and Geoff for their sieves; Phil Carmody for some Perl wizardry
* Xyzzy for allowing and managing this great message board

Anyone wanting to do some "321" crunching can head over to PrimeGrid, where their help will be welcomed.