mersenneforum.org Sieving drive Riesel base 6 n=150K-1M
 Register FAQ Search Today's Posts Mark Forums Read

 2009-08-14, 05:40 #1 gd_barnes     May 2007 Kansas; USA 3·19·179 Posts Sieving drive Riesel base 6 n=150K-1M This is a sieving drive for the 8 k's remaining on Riesel base 6 for n=150K-1M. Karsten kindly provided his file that is sieved to P=0.8T as a starting point. Sieving up to P=43T is needed for the n=500K-1M range for the 5 remaining k's. Like before, sr2sieve is what we will use. It is recommended that you run 64-bit sr2sieve on a 64-bit machine. Let us know if you need the executable or more detailed instructions on using it. Here is an example of the command to execute at the command prompt: sr2sieve -p 35e12 -P 40e12 -i sieve-riesel-base6-500K-1M.txt The above would be if you were sieving P=35T-40T. The file is listed after the "-i" command and is the actual file name that is posted in a link below. Feel free to name it something shorter if you want or use the "srwork" older convention where you don't have to specify a file name. When complete, you should have a factors.txt file. Just post the file here in this thread or if it is too big, please Email the file to me at: gbarnes017 at gmail dot com A P=1T range should take ~2 CPU days on a modern 64-bit machine. Please reserve ranges in multiples of P=1T and plan to reserve no more than ~7-10 days of work at a time. When making reservations, please post your estimated completion date. This can be seen in sr2sieve about one minute after you start your sieve. Here is a link to the latest sieve file: http://www.noprimeleftbehind.net/cru...e6-500K-1M.txt. All factors up to P=43T have been removed. We will remove additional factors as the drive progresses to slightly speed up sieving. Reservations: Code:  P-range reserved by status est. completion date 0T-0.8T kar_bon complete 0.8T-32T Lennart complete 32T-35T gd_barnes complete 35T-39T Flatlander complete 39T-43T Batalov complete The sieving drive is complete! This is a very exciting base that can easily be proven within the next few years. All help is greatly appreciated! Thank you, Gary Last fiddled with by gd_barnes on 2010-06-27 at 02:21 Reason: update status
 2009-08-14, 09:41 #2 gd_barnes     May 2007 Kansas; USA 3·19·179 Posts Important note about the sieve file: Although it is included in the file, k=1597 was only sieved to n=500K. If anyone would like to take on the task of sieving just this one k for n=500K-1M up to our current sieving limit for the drive, let me know and we'll keep a non-formal posting about what ranges are being done and who is doing them if more than one person. Gary
2009-08-14, 11:17   #3
Lennart

"Lennart"
Jun 2007

25·5·7 Posts

Quote:
 Originally Posted by gd_barnes Important note about the sieve file: Although it is included in the file, k=1597 was only sieved to n=500K. If anyone would like to take on the task of sieving just this one k for n=500K-1M up to our current sieving limit for the drive, let me know and we'll keep a non-formal posting about what ranges are being done and who is doing them if more than one person. Gary

I take k 1597

Lennart

 2009-08-14, 15:58 #4 Lennart     "Lennart" Jun 2007 25×5×7 Posts I have done k=1597 to 800G I start sieve all from 800G-3T Lennart
 2009-08-14, 18:51 #5 gd_barnes     May 2007 Kansas; USA 27DB16 Posts Thanks for the huge boost Lennart.
2009-08-15, 20:17   #6
Lennart

"Lennart"
Jun 2007

21408 Posts
Sieved to 6T

Here is the file sieved to 6T

Lennart
Attached Files
 sieve-riesel-base6-150K-1000K_6T.abcd.zip (78.7 KB, 84 views)

 2009-08-18, 01:35 #7 gd_barnes     May 2007 Kansas; USA 3·19·179 Posts Thanks a bunch Lennart! To all: In the next few hours, we'll start a drive for Riesel base 6 starting from n=150K on the final 8 k's remaining. With such a low base and few k's remaining, this one has a very good possibility of being proven over the next few years. As a SWAG without doing any math or calculation, I would put its final prime in the vicinity of n=~10M. Gary Last fiddled with by gd_barnes on 2009-08-18 at 02:08
2009-08-18, 05:33   #8
mdettweiler
A Sunny Moo

Aug 2007
USA (GMT-5)

3·2,083 Posts

Quote:
 Originally Posted by gd_barnes As a SWAG without doing any math or calculation, I would put its final prime in the vicinity of n=~10M.
YOWCH! Even with the new and improved PFGW, a test at that size for base 6 would probably take days to complete. Of course, that's not factoring in any expected increases in computer technology between now and when we get near that point.

2009-08-18, 06:30   #9
gd_barnes

May 2007
Kansas; USA

3×19×179 Posts

Quote:
 Originally Posted by mdettweiler YOWCH! Even with the new and improved PFGW, a test at that size for base 6 would probably take days to complete. Of course, that's not factoring in any expected increases in computer technology between now and when we get near that point.
That is a very big SWAG and this particular base has a somewhat unique issue that makes it a little trickier than one might expect for as prime as it is. That of k=1597. See last para.

I agree with your comments but believe me, that is very good for most of the bases here. I think there's a reasonable chance that we could prove it in 10-20 years depending on how much we dedicate to it.

That's for the Riesel side but on the Sierp side, with 28 k's remaining, it likely will not be proven in any of our lifetimes even allowing for computer speed increases and improvements in software unless new mathematical methods are discovered for searching the bases. Even if it was base 2, it would likely be more difficult than the Riesel side.

People don't realize how hard it is to knock out the final k's on these bases. Even for a fairly prime base like base 6, it's tough because the final few k's are almost always very low weight.

Consider that there are only 5128 pairs remaining for the entire n=150K-1M range for k=1597 on a sieve to P=6T. k=1597 will be the key as it is by far the lowest weight k remaining. If we can pick up a prime for it for n<=1M, then there's a reasonable chance that we could find them all by n=3M to 5M. If not, well, this may end up being yet another base that we have one k remaining on for an extended period.

All of that said, I still consider base 6 to be very exciting because it is the only truly "low" base that is kind of difficult to prove but not so overwhelmingly so that one side can't be done in our lifetimes. In this case, I define "low" as < 8. All other bases < 8 will be terribly difficult to prove in many lifetimes (Sierp base 2 has a chance but still a somewhat low chance at this point since it's already at n>10M with 5 k's remaining). I believe these "somewhat difficult" bases are the most interesting. An example is the Dual Sierp base 2 project with 3 k's remaining at n=~3M. I think that one has a good chance of being proven by perhaps the n=20M to 30M range. In other words, it's tough but not too tough, the most interesting kind.

Gary

Last fiddled with by gd_barnes on 2009-08-18 at 06:42

2009-08-18, 14:43   #10
mdettweiler
A Sunny Moo

Aug 2007
USA (GMT-5)

141518 Posts

Quote:
 Originally Posted by gd_barnes That is a very big SWAG and this particular base has a somewhat unique issue that makes it a little trickier than one might expect for as prime as it is. That of k=1597. See last para. I agree with your comments but believe me, that is very good for most of the bases here. I think there's a reasonable chance that we could prove it in 10-20 years depending on how much we dedicate to it. That's for the Riesel side but on the Sierp side, with 28 k's remaining, it likely will not be proven in any of our lifetimes even allowing for computer speed increases and improvements in software unless new mathematical methods are discovered for searching the bases. Even if it was base 2, it would likely be more difficult than the Riesel side. People don't realize how hard it is to knock out the final k's on these bases. Even for a fairly prime base like base 6, it's tough because the final few k's are almost always very low weight. Consider that there are only 5128 pairs remaining for the entire n=150K-1M range for k=1597 on a sieve to P=6T. k=1597 will be the key as it is by far the lowest weight k remaining. If we can pick up a prime for it for n<=1M, then there's a reasonable chance that we could find them all by n=3M to 5M. If not, well, this may end up being yet another base that we have one k remaining on for an extended period. All of that said, I still consider base 6 to be very exciting because it is the only truly "low" base that is kind of difficult to prove but not so overwhelmingly so that one side can't be done in our lifetimes. In this case, I define "low" as < 8. All other bases < 8 will be terribly difficult to prove in many lifetimes (Sierp base 2 has a chance but still a somewhat low chance at this point since it's already at n>10M with 5 k's remaining). I believe these "somewhat difficult" bases are the most interesting. An example is the Dual Sierp base 2 project with 3 k's remaining at n=~3M. I think that one has a good chance of being proven by perhaps the n=20M to 30M range. In other words, it's tough but not too tough, the most interesting kind. Gary
Ah, that makes sense now. Thanks for the explanation!

 2009-09-29, 08:47 #11 gd_barnes     May 2007 Kansas; USA 237338 Posts The Riesel base 6 drive is closing in on completion to n=500K. Therefore we will need additional sieving for the n=500K-1M portion of the file. The optimum sieve depth for breaking off the n=500K-750K range is P=50T. We (mostly Lennart) have already sieved up to P=32T. A P=1T range should take ~2 CPU days and we are asking that people reserve ranges in at least P=1T increments. I am reserving P=32T-35T for one core. ETA is Oct. 5th. Any and all help is greatly appreciated. Thank you, Gary Last fiddled with by gd_barnes on 2009-09-29 at 09:12

 Similar Threads Thread Thread Starter Forum Replies Last Post gd_barnes Conjectures 'R Us 401 2015-05-27 15:15 gd_barnes Conjectures 'R Us 213 2014-02-26 09:35 gd_barnes Conjectures 'R Us 40 2011-01-22 08:10 gd_barnes Conjectures 'R Us 13 2009-12-14 09:23 gd_barnes Conjectures 'R Us 199 2009-09-30 18:44

All times are UTC. The time now is 20:37.

Tue Sep 22 20:37:04 UTC 2020 up 12 days, 17:48, 0 users, load averages: 2.02, 1.91, 1.85