Question about twinsieve

hunson · 2020-04-09, 11:51

Hey,

I am experimenting a bit with twinsieve.exe.
I tried the following command: twinsieve.exe -k 1 -K 100000000 -b 2 -n 268768 -P 1e14 -W 12
After a while I got this this error message.

Quote:

p=6057931104593, 53.01M p/sec, 99902590 factors found at 3.15 sec per factor, 6.1% done. ETC 2020-04-10 04:47
Fatal Error: Something is wrong. Counted terms (96257) != expected terms (97304)

Can someone please explain to me what I did wrong ? Sieving for -k 1 -K 10000000 -P 1e12 for the same base resulted in no error.

Thanks in advance.

rogue · 2020-04-09, 12:52

Quote:

Originally Posted by hunson

I am experimenting a bit with twinsieve.exe.
I tried the following command: twinsieve.exe -k 1 -K 100000000 -b 2 -n 268768 -P 1e14 -W 12
After a while I got this this error message.

Can someone please explain to me what I did wrong ? Sieving for -k 1 -K 10000000 -P 1e12 for the same base resulted in no error.

Which version and build date? I will have to take a look.

hunson · 2020-04-09, 13:41

Hey,

twinsieve is from the mtsieve-framework version 1.9.5, version 1.2.
Sorry can't find the build date.

My machine:
Win10-64bit
AMD Ryzen 3600 (6 cores, 12 threads)

16 GB RAM

Thanks for helping out.

pepi37 · 2020-04-12, 13:55

Quote:

Originally Posted by hunson

Hey,

twinsieve is from the mtsieve-framework version 1.9.5, version 1.2.
Sorry can't find the build date.

My machine:
Win10-64bit
AMD Ryzen 3600 (6 cores, 12 threads)

16 GB RAM

Thanks for helping out.

Old bug you must use start point that is not even

hunson · 2020-04-12, 15:38

What start point do you mean ? In my case k is not even and works for smaller ranges (1-10.000.000).

rogue · 2020-04-12, 16:42

Quote:

Originally Posted by hunson

twinsieve is from the mtsieve-framework version 1.9.5, version 1.2.

Try 1.9.6 (assuming I posted it). I fixed a patch when using multiple threads. I haven't had time to try to reproduce this.

Note that for twinsieve, it might be difficult to get maximum utilization from multiple threads due to how fast it goes thru a chunk of work.

rogue · 2020-04-12, 20:37

I ran a test with 1.9.6 framework. No issues. This means that either the bug has been fixed or I don't have the right conditions for reproducing it.

pepi37 · 2020-04-12, 22:39

Quote:

Originally Posted by rogue

I ran a test with 1.9.6 framework. No issues. This means that either the bug has been fixed or I don't have the right conditions for reproducing it.

I cannot find 1.9.6

e:\MTSIEVE\mtsieve1957\twin>twinsieve -P10000000000 -W6 -k 6 -K 990000000 -n 50000 -b10 -fN -r -o twinb10.txt
twinsieve v1.2, a program to find factors of k*b^n+1/-1 numbers for fixed b and n and variable k
Sieve started: 1 < p < 1e10 with 890999995 terms (6 < k < 990000000, k*10^50000) (expecting 864178223 factors)
Sieve completed at p=10000000019.
Processor time: 104.38 sec. (3.52 sieving) (1.93 cores)
Fatal Error: Something is wrong. Counted terms (2331345) != expected terms (2349970)

rogue · 2020-04-12, 23:10

I posted 1.9.6 executables on the mtsieve home page. Hopefully that resolves the multi-threading issue.

pepi37 · 2020-04-12, 23:22

Quote:

Originally Posted by rogue

I posted 1.9.6 executables on the mtsieve home page. Hopefully that resolves the multi-threading issue.

Speed is same...as CPU usage.

rogue · 2020-04-13, 00:16

Quote:

Originally Posted by pepi37

Speed is same...as CPU usage.

I would not expect any speed gains. The best way to gain speed with this sieve is to do one of two things:

1) Run multiple copies then use the factor files to eliminate terms.
2) When running one copy, use -w to increase the number of primes per chunk of work.

In any case I'm hoping that the Fatal Error is gone.

2020-04-09, 13:41	#3
hunson Feb 2020 Germany 2³×7 Posts	Hey, twinsieve is from the mtsieve-framework version 1.9.5, version 1.2. Sorry can't find the build date. My machine: Win10-64bit AMD Ryzen 3600 (6 cores, 12 threads) 16 GB RAM Thanks for helping out.

2020-04-12, 15:38	#5
hunson Feb 2020 Germany 56₁₀ Posts	What start point do you mean ? In my case k is not even and works for smaller ranges (1-10.000.000).

2020-04-12, 20:37	#7
rogue "Mark" Apr 2003 Between here and the 2·3·1,223 Posts	I ran a test with 1.9.6 framework. No issues. This means that either the bug has been fixed or I don't have the right conditions for reproducing it.

2020-04-12, 23:10	#9
rogue "Mark" Apr 2003 Between here and the 2×3×1,223 Posts	I posted 1.9.6 executables on the mtsieve home page. Hopefully that resolves the multi-threading issue.