mtsieve

[rogue]

Originally Posted by pepi37

Last night I run Newpgen with same range for SG search and your new sgsieve.
Since I don't know does your sieve include odd k I make two test and found totally different number of candidates in output ( on same sieve depth)
So decoding ABCD was unsuccessful because I have no base point to decode.

Only odd k are included in sgsieve. I can run against newpgen and see what it produces.

[rogue]

I posted 2.0.5 to sourceforge. The only change is for sgsieve support of newpgen format. Note that the Sophie-Germain primes it searches for are referred to a "CC" by newpgen and twingen. In the future I will add support for p = k*b^n-1. Right now it only supports p = k*2^n+1. The future will also bring support for other bases.

[Citrix]

Feature request for srsieve2.exe

In CisOneSubsequenceHelper.cpp can you create an option to bypass the code to calculate the ii_BestQ if the user can use the -Q flag and specify it from the command line.

Generally srsieve2.exe program can calculate the best Q but for some sequences (Q>720) it does not work and it might be better to specify it from the command line.

Thanks.

[rogue]

Originally Posted by Citrix

Feature request for srsieve2.exe

In CisOneSubsequenceHelper.cpp can you create an option to bypass the code to calculate the ii_BestQ if the user can use the -Q flag and specify it from the command line.

Generally srsieve2.exe program can calculate the best Q but for some sequences (Q>720) it does not work and it might be better to specify it from the command line.

Seems reasonable enough. Do you know some sequences where Q > 720? It might be possible for srsieve2 to compute it, unless it would be extremely large.

[Citrix]

Originally Posted by rogue

Seems reasonable enough. Do you know some sequences where Q > 720? It might be possible for srsieve2 to compute it, unless it would be extremely large.

All candidates in post below need Q >720
https://www.mersenneforum.org/showpo...82&postcount=4

You can read the posts in the above thread (towards the end). We were finding benefit of using Q values greater than 50,000

You can also artificially create a sequence that needs Q>720 for testing

It would be best for a manual option for Q as some sequences require Q to be a multiple of 7,11 etc and it is hard for any algorithm to predict best Q in all possible circumstances.

[pepi37]

Source 2.0.5.7
I cannot get that gfndsievecl. exe working
Ok it doesnot crash, but if use GPU then GPU load should not be zero?

[rogue]

Originally Posted by pepi37

Source 2.0.5.7
I cannot get that gfndsievecl. exe working
Ok it doesnot crash, but if use GPU then GPU load should not be zero?

The first chunk that is tested will not use the GPU because of the large number of candidates removed. Beyond that it should use the GPU. Did you specify the -G option? Also note that this code doesn't stress the GPU that much. You could try upping the value for -G to start more GPU workers.

[pepi37]

Originally Posted by rogue

The first chunk that is tested will not use the GPU because of the large number of candidates removed. Beyond that it should use the GPU. Did you specify the -G option? Also note that this code doesn't stress the GPU that much. You could try upping the value for -G to start more GPU workers.

Yes it works , with -G2 -g 20 I got same speed as from one cpu worker!
Thanks for answer!


Cosmetic bug: if you use-i gfnd.pfgw -o gfnd.pfgw then output will be named gfnd.pfgw.pfgw, so you must use -o gfnd to get output gfnd.pfgw

[rogue]

Originally Posted by pepi37

Yes it works , with -G2 -g 20 I got same speed as from one cpu worker!
Thanks for answer!

Cosmetic bug: if you use-i gfnd.pfgw -o gfnd.pfgw then output will be named gfnd.pfgw.pfgw, so you must use -o gfnd to get output gfnd.pfgw

You probably want to bump both -G and -g.

Auto-appending .pfgw to the output file name is intended in this case because of the -T option. I suppose I could change so that .pfgw is only appended if -T is specified thus making -O a prefix for file name instead of a file name.

[pepi37]

Originally Posted by rogue

You probably want to bump both -G and -g.

Auto-appending .pfgw to the output file name is intended in this case because of the -T option. I suppose I could change so that .pfgw is only appended if -T is specified thus making -O a prefix for file name instead of a file name.

I try that but got error: my card has only 6 GB of DDR6 , so it broke: it looks like 6 GB is not enough. On current settings it use 4 GB of RAM

By the way how to activate
-x --testterms test remaining terms for GFN divisibility

Can I just input number of candidate and try to test it without sieving or I need to done sieving and in next step application test remain candidates?

e:\MTSIEVE\GFDN>gfndsievecl.exe -i gfnd.pfgw -x
gfndsieve v1.8, a program to find factors of k*2^n+1 numbers for variable k and n
Fatal Error: cannot use -i and -x together

e:\MTSIEVE\GFDN>pause

I try other combination but it doesnot work also :(

[rogue]

The reason is that -x is intended to be used on new sieves. It is also geared towards n < 2000. For larger n using gfndsieve+pfgw would be faster. Also other programs will likely be faster than gfndsieve for such small x.