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Old 2021-09-21, 19:02   #3114
Batalov
 
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Quote:
Originally Posted by bur View Post
Interesting, is it valid for most sizes of numbers? That'd be quite helpful.
Yeah, there are a few threads over years to the same effect. It is.

For smaller numbers/projects, it is very difficult to hit the exact cusp, so the usual rule of thumb for automatic scripts is "if you got the matrix, don't try to sieve extra - it will be a wash" (given that filtering itself is an overhead and together with sieving some more - you will not get any time savings). but for large projects, there can be a huge difference.

One could check logs that are kept in NFS @ Home collection, while binning for similar size, and very rarely you would see that the runner get a very large matrix and still decides to go along with it, and that's of course a fine personal preference. It depends on resources available to the runner; sometimes it is - optimizing for their own. human time, and sometimes it is the external resources (at the expense of human time for doing filtering twice or more).

Many logs (very educationally!) keep several recordings of filtering.
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Old 2021-09-21, 19:10   #3115
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Quote:
Originally Posted by charybdis View Post
What Q value have you sieved up to, and what is the overall duplication rate like? I'd be interested to know how well my estimates from test-sieving have held up.
That's unfortunately a bit tough to answer, due to the distributed nature of my sieving setup.

In any case, I now have a filtering run going with target_density=130 and 2.024B uniques. If this succeeds, I will hopefully be able to hand it off for frmky for LA.
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Old 2021-09-23, 16:09   #3116
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Update: with 2.024B uniques and target_density=130, msieve produces a 133.3M x 133.3M matrix:

Code:
Wed Sep 22 18:39:19 2021  commencing 2-way merge
Wed Sep 22 18:43:22 2021  reduce to 304431703 relation sets and 296088199 unique ideals
Wed Sep 22 18:43:22 2021  commencing full merge
Wed Sep 22 20:02:23 2021  memory use: 32549.0 MB
Wed Sep 22 20:02:54 2021  found 134281671 cycles, need 133304399
Wed Sep 22 20:03:51 2021  weight of 133304399 cycles is about 17329637475 (130.00/cycle)
Wed Sep 22 20:03:51 2021  distribution of cycle lengths:
Wed Sep 22 20:03:51 2021  1 relations: 4545972
Wed Sep 22 20:03:51 2021  2 relations: 7597027
Wed Sep 22 20:03:51 2021  3 relations: 9794025
Wed Sep 22 20:03:51 2021  4 relations: 10584633
Wed Sep 22 20:03:51 2021  5 relations: 11171953
Wed Sep 22 20:03:51 2021  6 relations: 11129931
Wed Sep 22 20:03:51 2021  7 relations: 10851523
Wed Sep 22 20:03:51 2021  8 relations: 10319041
Wed Sep 22 20:03:51 2021  9 relations: 9582186
Wed Sep 22 20:03:51 2021  10+ relations: 47728108
Wed Sep 22 20:03:51 2021  heaviest cycle: 25 relations
Wed Sep 22 20:04:20 2021  commencing cycle optimization
I think we're at the point of diminishing returns, and frmky has graciously offered to help with the LA at this point.
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Old 2021-10-01, 21:08   #3117
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frmky reports that this is now in LA on a multi-GPU system, with ~170 hours to go, plus or minus some time depending on his cluster's queueing.
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Old 2021-10-02, 16:42   #3118
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Nice, let's hope the 7 will vanish....
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Old 2021-10-02, 17:08   #3119
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It can't - the 2^2 guarantees sigma(n) is divisible by sigma(2^2) = 7, so the next term which is sigma(n)-n will also be divisible by 7. Similarly the 7 means that sigma(n) will be divisible by 8, so the next term will also have exactly two factors of 2.

To get rid of the 2^2*7 we would need a term where the 7 is raised to an even power and the remaining prime factors contribute at most two factors of 2 to sigma(n).
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Old 2021-10-04, 07:44   #3120
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Quote:
Originally Posted by ryanp View Post
frmky reports that this is now in LA on a multi-GPU system, with ~170 hours to go, plus or minus some time depending on his cluster's queueing.
Curiously,
Code:
linear algebra completed 103057 of 127518005 dimensions (0.1%, ETA 75h33m)
That's on 160 (!) A64FX nodes. Unfortunately I can't use that many for 3 days...
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Old 2021-10-04, 12:22   #3121
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Quote:
Originally Posted by frmky View Post
Curiously,
Code:
linear algebra completed 103057 of 127518005 dimensions (0.1%, ETA 75h33m)
That's on 160 (!) A64FX nodes. Unfortunately I can't use that many for 3 days...
Still, pretty fun to see them chew through a matrix of this size so quickly!

How's the other run progressing?
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Old 2021-10-04, 18:44   #3122
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Quote:
Originally Posted by ryanp View Post
How's the other run progressing?
Live off the cluster:
Code:
linear algebra completed 60978666 of 127518005 dimensions (47.8%, ETA 90h39m)
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Old 2021-10-04, 22:45   #3123
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Ryan-
Now that sieving was shut down, do you have even a rough guess for Q-range that was sieved? Or the number of raw relations?
It's nice to have confirmation that 2G uniques was enough for this job; that means we can go 35/35 and still use msieve for a future C22x GNFS job.
Also, did you do any A=32 sieving, or all I=16 (same as A=31)?

Last fiddled with by VBCurtis on 2021-10-04 at 22:45
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Old 2021-10-05, 12:40   #3124
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Quote:
Originally Posted by VBCurtis View Post
Ryan-
Now that sieving was shut down, do you have even a rough guess for Q-range that was sieved? Or the number of raw relations?
Unfortunately I don't have a log of this now, but I can keep one for future jobs.

My methodology is essentially: fire off a large number of CADO jobs with different q ranges in parallel, then periodically gather the gzipped files, concatenate and remdups4 the merged file, and try an msieve run. Then wait a few hours and repeat. Unfortunately, I don't have the logs of the remdups4 output now.
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