Sieving discussion thread - Page 7

MooMoo2 · 2007-01-20, 00:41

Quote:

Originally Posted by Skligmund

The instructions are confusing at best. I know this is the wrong thread for this, but it only made sense here. If anybody knows how this works, let me know. Maybe make a simple tutorial for it?

I hope this tutorial helps (written by jmblazek):

http://www.elaurian.org/tpsieving/

jmblazek · 2007-01-20, 00:48

Quote:

Originally Posted by MooooMoo

I hope this tutorial helps (written by jmblazek):

http://www.elaurian.org/tpsieving/

sieve across several machines...duplicate and merge...
I'll see if I can add that to the page.

Skligmund · 2007-01-20, 02:57

Thanks guys.

The reason I ask is I run across 7 cores (5 computers) and I think I could really reduce the size of that 736MB file. If I was able to merge all my files together, I could probably be down at 730 or less already, but I only get one range worth (usually like 200 kilobytes or something) instead of 7 ranges worth (1400 KB ish). After a while, it adds up.

jmblazek · 2007-01-20, 05:17

Quote:

Originally Posted by jmblazek

sieve across several machines...duplicate and merge...
I'll see if I can add that to the page.

done...let me know if it is clear.

http://www.elaurian.org/tpsieving/

Skligmund · 2007-01-20, 07:54

Ah hah!

I was doing everything manually, I just didn't understand how to merge all the files. Now I know! Thanks for the tutorial. I shall use it when all my subranges complete.

pacionet · 2007-01-20, 13:56

What is the "Verify result" option in NewPGen ? Should we use it ?

jmblazek · 2007-01-20, 14:54

from the NewPGen Help/Contents page:

If "Verify results" is checked, NewPGen will do a careful check to make sure that the prime actually does divide the number that it thinks it does. This will make NewPGen very slightly slower, but it is recommended that it is always checked, particularly as p gets large (where the scope for programming errors increases), and only uncheck it during the early parts of the sieving if you are using a primorial mode and many k's are being thrown out every second. If you are not using a primorial sieve then leave this checked, as then it makes no difference to NewPGen's performance.

"particularly as p gets large" That means what??? 500T, 1P, 10P???

Let me know when and if it should be checked and I'll note it on the help page.

MooMoo2 · 2007-01-20, 19:28

Quote:

Originally Posted by jmblazek

from the NewPGen Help/Contents page:

If "Verify results" is checked, NewPGen will do a careful check to make sure that the prime actually does divide the number that it thinks it does. This will make NewPGen very slightly slower, but it is recommended that it is always checked, particularly as p gets large (where the scope for programming errors increases), and only uncheck it during the early parts of the sieving if you are using a primorial mode and many k's are being thrown out every second. If you are not using a primorial sieve then leave this checked, as then it makes no difference to NewPGen's performance.

"particularly as p gets large" That means what??? 500T, 1P, 10P???

Let me know when and if it should be checked and I'll note it on the help page.

It doesn't need to be checked if we can come up with a factor verification script.

gribozavr · 2007-01-20, 19:42

I will check all factors when I will be preparing files for PG.

smh · 2007-01-20, 22:18

Quote:

Originally Posted by gribozavr

I will check all factors when I will be preparing files for PG.

How can you check all factors? If i send you my newpgen output file, you would have to refactor all numbers I removed?

gribozavr · 2007-01-20, 22:28

We plan to collect newpgen.del files.

2007-01-20, 14:54	#73
jmblazek Nov 2006 Earth 2⁶ Posts	from the NewPGen Help/Contents page: If "Verify results" is checked, NewPGen will do a careful check to make sure that the prime actually does divide the number that it thinks it does. This will make NewPGen very slightly slower, but it is recommended that it is always checked, particularly as p gets large (where the scope for programming errors increases), and only uncheck it during the early parts of the sieving if you are using a primorial mode and many k's are being thrown out every second. If you are not using a primorial sieve then leave this checked, as then it makes no difference to NewPGen's performance. "particularly as p gets large" That means what??? 500T, 1P, 10P??? Let me know when and if it should be checked and I'll note it on the help page. Last fiddled with by jmblazek on 2007-01-20 at 15:15

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2007-01-20, 02:57	#69
Skligmund Dec 2006 Anchorage, Alaska 78₁₀ Posts	Thanks guys. The reason I ask is I run across 7 cores (5 computers) and I think I could really reduce the size of that 736MB file. If I was able to merge all my files together, I could probably be down at 730 or less already, but I only get one range worth (usually like 200 kilobytes or something) instead of 7 ranges worth (1400 KB ish). After a while, it adds up.

2007-01-20, 07:54	#71
Skligmund Dec 2006 Anchorage, Alaska 2×3×13 Posts	Ah hah! I was doing everything manually, I just didn't understand how to merge all the files. Now I know! Thanks for the tutorial. I shall use it when all my subranges complete.

2007-01-20, 13:56	#72
pacionet Oct 2005 Italy 153₁₆ Posts	What is the "Verify result" option in NewPGen ? Should we use it ?

2007-01-20, 19:42	#75
gribozavr Mar 2005 Internet; Ukraine, Kiev 11·37 Posts	I will check all factors when I will be preparing files for PG.

2007-01-20, 22:28	#77
gribozavr Mar 2005 Internet; Ukraine, Kiev 11·37 Posts	We plan to collect newpgen.del files.