mersenneforum.org  

Go Back   mersenneforum.org > Search Forums

Showing results 1 to 25 of 498
Search took 0.07 seconds.
Search: Posts Made By: charybdis
Forum: Factoring 2021-10-19, 13:43
Replies: 60
Views: 4,174
Posted By charybdis
Indeed lambda is applied before the size of the...

Indeed lambda is applied before the size of the cofactor is known exactly - as you're probably aware, some crude but clever approximations are used for log2 during sieving.

I don't know why...
Forum: Cunningham Tables 2021-10-19, 12:44
Replies: 107
Views: 33,628
Posted By charybdis
Thanks Oliver for getting everything set up! ...

Thanks Oliver for getting everything set up!

Using commit 9e81c910 isn't essential, but I would highly recommend that everyone upgrades to it, because it speeds up sieving by several percent...
Forum: Factoring 2021-10-19, 10:37
Replies: 60
Views: 4,174
Posted By charybdis
Worth noting here that adding 1 to each mfb may...

Worth noting here that adding 1 to each mfb may do basically nothing if the lambdas are too small. Maybe add 0.05 to each lambda at the same time.
Forum: Factoring 2021-10-18, 22:38
Replies: 60
Views: 4,174
Posted By charybdis
For GNFS it appears to be in the high 160s, so...

For GNFS it appears to be in the high 160s, so there's probably a way to go. CADO will always give higher duplication rates than ggnfs because it sieves below the FB bound.
Forum: Factoring 2021-10-18, 20:51
Replies: 60
Views: 4,174
Posted By charybdis
The E score for this number would be more typical...

The E score for this number would be more typical for GNFS ~c146 (comparison is fine assuming you're still using deg 5) so your lims, lpbs and mfbs may be on the small side. As henryzz alluded to, at...
Forum: Aliquot Sequences 2021-10-16, 17:21
Replies: 133
Views: 45,438
Posted By charybdis
Agreed. This is over 3 times harder than 3,748+...

Agreed. This is over 3 times harder than 3,748+ so let's get that done first.

Alternatively Ryan and Greg could probably factor this number in under 2 weeks if they want.
Forum: Homework Help 2021-10-15, 16:30
Replies: 14
Views: 636
Posted By charybdis
I can't think of any cases where this would be...

I can't think of any cases where this would be useful for the numbers that we usually run SNFS on. You can't just switch out the linear polynomial for a quadratic one. The solution (as far as it is...
Forum: Homework Help 2021-10-14, 14:37
Replies: 14
Views: 636
Posted By charybdis
It is not an equation. It is a polynomial. An...

It is not an equation. It is a polynomial. An equation implies that two things are being equated. A polynomial does not contain an equals sign.

I'm not sure what you're asking. The linear...
Forum: CADO-NFS 2021-10-13, 00:44
Replies: 3
Views: 286
Posted By charybdis
CADO does use GMP, but if a new GMP version...

CADO does use GMP, but if a new GMP version caused issues I seriously doubt they would be server issues. What CADO revision are you running?
Forum: Aliquot Sequences 2021-10-12, 19:25
Replies: 3,136
Views: 255,799
Posted By charybdis
Happy to leave it for you. While I remember...

Happy to leave it for you.

While I remember - Greg do you have the c220 postprocessing log to hand?
Forum: Aliquot Sequences 2021-10-12, 14:50
Replies: 3,136
Views: 255,799
Posted By charybdis
:bow: Congrats Ryan and Greg on an enormous...

:bow:

Congrats Ryan and Greg on an enormous job! I make that the 7th largest public GNFS ever?

Anyone working the c163 on the next line?
Forum: CADO-NFS 2021-10-10, 12:46
Replies: 2
Views: 208
Posted By charybdis
The way I understand it, "polyselect" performs...

The way I understand it, "polyselect" performs the equivalent of np1 and nps, "sopt" does the equivalent of nps alone, and "polyselect_ropt" is equivalent to npr. The CADO script runs polyselect...
Forum: Msieve 2021-10-09, 00:12
Replies: 185
Views: 52,732
Posted By charybdis
I have a 1.098e-12 that I never bothered to post...

I have a 1.098e-12 that I never bothered to post because (a) it was hardly an improvement and (b) I figured that with no updates for several years people weren't really keeping track of records below...
Forum: NFS@Home 2021-10-07, 23:18
Replies: 82
Views: 9,814
Posted By charybdis
Same here - well spotted Jon. Didn't even look at...

Same here - well spotted Jon. Didn't even look at the job name; the "35" should have set alarm bells ringing.

The cownoise poly generator appears to automatically generate quartics for exponents...
Forum: CADO-NFS 2021-10-07, 17:56
Replies: 70
Views: 13,214
Posted By charybdis
The way I tested this was to look at the CPU-time...

The way I tested this was to look at the CPU-time stats in the logfile ('stats_total_cpu_time') to find ranges that took almost exactly the same length of time to sieve, and then see which of these...
Forum: NFS@Home 2021-10-04, 14:48
Replies: 82
Views: 9,814
Posted By charybdis
Using composite special-q will also lead to a...

Using composite special-q will also lead to a high duplication rate. It's a useful way to squeeze out a few more relations when yield is low due to suboptimal parameters (eg artificially low lpb and...
Forum: NFS@Home 2021-10-04, 13:30
Replies: 82
Views: 9,814
Posted By charybdis
The normalized relations formula is not...

The normalized relations formula is not applicable when composite special-q are being used, as it is based on the premise that special-q have the same frequency as primes.
Forum: NFS@Home 2021-10-03, 12:51
Replies: 82
Views: 9,814
Posted By charybdis
Very nicely done; glad to be wrong about GNFS vs...

Very nicely done; glad to be wrong about GNFS vs SNFS in this case.



Is this normal for the 16e-small queue?
Forum: Aliquot Sequences 2021-10-02, 17:08
Replies: 3,136
Views: 255,799
Posted By charybdis
It can't - the 2^2 guarantees sigma(n) is...

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...
Forum: NFS@Home 2021-10-02, 00:46
Replies: 82
Views: 9,814
Posted By charybdis
Aha, good to know. Sorry if I confused anyone. ...

Aha, good to know. Sorry if I confused anyone.

Never mind the parameter choice for the quartic, I'm surprised this isn't obviously better by GNFS. While it isn't a perfect reflection of...
Forum: NFS@Home 2021-10-01, 20:48
Replies: 82
Views: 9,814
Posted By charybdis
This should be lpbr/lpba 34/32 - not 32/34 which...

This should be lpbr/lpba 34/32 - not 32/34 which would be more appropriate for an octic. (the larger the degree the larger the algebraic side)

Msieve is fine with 34-bit large primes; it's the...
Forum: YAFU 2021-09-29, 21:48
Replies: 15
Views: 1,423
Posted By charybdis
The Windows BOINC sievers work fine on octics,...

The Windows BOINC sievers work fine on octics, and the Linux tasks error out. On small jobs like this that isn't an issue. For the 16e v5 queue, which often only sieves one number at a time for...
Forum: YAFU 2021-09-29, 20:23
Replies: 15
Views: 1,423
Posted By charybdis
Octic-280... interesting. Of course this number...

Octic-280... interesting. Of course this number doesn't have a quartic, but there has been a bit of discussion this year about where the quartic/octic crossover might lie, especially with regard to...
Forum: Lounge 2021-09-29, 15:09
Replies: 321
Views: 51,485
Posted By charybdis
The expectation reaches 52 at p=154772617. For...

The expectation reaches 52 at p=154772617. For the exponents that have been tested so far it is pretty close to 51.
Forum: Lounge 2021-09-29, 12:58
Replies: 321
Views: 51,485
Posted By charybdis
I think a lot of the speculation about the...

I think a lot of the speculation about the heuristic being wrong arose from people applying the linear approximation to the heuristic, in which the log(ap) factor in the probability that Mp is prime...
Showing results 1 to 25 of 498

 
All times are UTC. The time now is 14:40.


Wed Oct 20 14:40:31 UTC 2021 up 89 days, 9:09, 0 users, load averages: 0.86, 1.29, 1.27

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.

This forum has received and complied with 0 (zero) government requests for information.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation.
A copy of the license is included in the FAQ.