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Currently, for my manual PPS sieving efforts, I'm using:
srsieve (dev version from mersenneforums)
PFGW
This is the process I use for large-candidate-set searches:
1) Sieve to pmax=1,000 with a range of 500,000 n's for a single k
2) Run through some trivial factoring with PFGW
3) Convert the file produced by PFGW to a sieve-able one via copying the *.out headers and converting with srfile
4) Sieving to remove false trivial primes
5) PRP testing
This is all performed on a single core - yet I have a quad core machine.
BTW: This whole process can get the list of candidates down to a few thousand within 60 seconds to a couple of minutes if done quickly enough.
Could anyone give me some advice on how I could speed up this process please? I have no GPU on this 64-bit laptop (and yes, 64-bit sieving is being performed). If anyone could give me some advice, I would appreciate it. |
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Use srsieve first.
An example to get started:
$ srsieve --newpgen --nmin 5000 --nmax 10000 --pmax 400000 "24*7^n+1"
This will sieve the single sequence 24*7^n+1 with n in the range 5,000 -
10,000 for all factors up to 400,000 and write the remaining terms in newpgen
format to the file t16_b7_k24.npg. It is equivalent (and should produce an
identical file) to the following NewPGen invocation:
When thats done use sr2sieve after 100G-400G
check files here http://sites.google.com/site/geoffreywalterreynolds/programs
Lennart |
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Thanks for the help. |
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rogueVolunteer developer
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Since you have a single k, I recommend sieving to a nominal depth p such that p > k, with srsieve, then switch to sr1sieve. It is much faster than srsieve for single k.
Also, I recommend d/ling the latest versions of srsieve/sr1sieve. I've made changes to Geoff's code that might benefit you. Look here for more information:
http://www.mersenneforum.org/showthread.php?t=15833 |
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Thanks for the tips. I'm using your version of srsieve already rogue, it's quite a bit faster!
One thing: do you already perform the algebraic factorizations, or do I need to add a switch to make it work? Also, your latest version of srsieve is crashing for me after a while, and it isn't reaching the pmax of about 1e12.
Also, how do you make it run properly (sr1sieve)? I can't get it to work. |
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sr1sieve -p1e9 -P10e9 -it16_b2_k5.npg -fk5_factor_1G-10G.txt -q
This is a example in a dos CMD window.
-p start p -P stop p -i input sievefile -f output factors file
you can also add -o filename and you get a resultfile with all factors removed.
-p --pmin P0
-P --pmax P1 Sieve for factors p in the range P0 <= p <= P1
-i --input FILE Read sieve from NewPGen format file FILE.
-o --output FILE Write sieve to NewPGen format file FILE.
-f --factors FILE Append new factors to file FILE.
-C --cache-file FILE Load (or save) Legendre symbol tables from (or to) FILE.
-s --save TIME Update output file every TIME (default 60) minutes.
-l --L1-cache SIZE Assume L1 data cache is SIZE Kb.
-L --L2-cache SIZE Assume L2 cache is SIZE Kb.
-B --baby METHOD Use METHOD for baby step mulmods.
-G --giant METHOD Use METHOD for giant step mulmods.
-H --hashtable SIZE Force use of a SIZE Kb hashtable.
-Q --subseq Q Force sieving k*b^n+c as subsequences (k*b^d)*(b^Q)^m+c.
-x --no-lookup Don't pre-compute Legendre symbol lookup tables.
-z --lower-priority Run at low priority. (-zz lower).
-Z --raise-priority Run at high priority. (-ZZ higher).
-A --affinity N Set affinity to CPU N.
-d --duplicates Report factors that don't eliminate any composite.
-q --quiet Don't print found factors.
-v --verbose Print some extra messages.
-h --help Print this help. |
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rogueVolunteer developer
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Thanks for the tips. I'm using your version of srsieve already rogue, it's quite a bit faster!
One thing: do you already perform the algebraic factorizations, or do I need to add a switch to make it work? Also, your latest version of srsieve is crashing for me after a while, and it isn't reaching the pmax of about 1e12.
Also, how do you make it run properly (sr1sieve)? I can't get it to work.
It will always remove candidates with algebraic factorizations, i.e. you can't control that behavior.
Are you using the Win64 build or did you build your own? I need to know what system you are running on. Could you also PM me the input files/switches you are are running with? |
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Also, how do you make it run properly (sr1sieve)? I can't get it to work.
This may be trivial, but just to make sure I will add this to what Lennart already posted: make sure your input file has the correct format (.npg). If not, use srfile to convert.
I would also suggest switching to sr1sieve sooner than p=1e12 as it is faster than srsieve for a single k.
____________
There are only 10 kinds of people - those who understand binary and those who don't
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rogueVolunteer developer
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I would also suggest switching to sr1sieve sooner than p=1e12 as it is faster than srsieve for a single k.
Once p > k, you can switch, but I would suggest sieving a little deeper so that the output file is smaller. |
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I apologise for not posting in a while, I was on a business trip in Germany and I had no internet connection (lousy 2-star hotel).
@rogue:
1) I create my own input files with srsieve
2) Running Win7 x64 on Intel Sandy Bridge laptop, I also have a desktop PC with Core2 Duo and an nVidia GTX 220 (I think it's CC1.3)
3) Using *.npg files, it now works fine.
4) How deep is deep enough? if k=1m, then pmax=1m<k<2m? (or something like that)?
@Lennart:
1) Thanks for the tips on the CMD line switches.
2) So, once done, do I just upload the factors or do I PRP test myself?
@[SG]:
1) I use srfile a lot now, thanks for the tip. |
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...an nVidia GTX 220 (I think it's CC1.3)
...
GT 220 (no GTX with that model number) is actually CC1.2
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