Sieve Benchmark Thread

[Lennart]

Originally Posted by axn

Ok. Here's the source code.

Currently sieves 1T upto p=100e6 in 50 minutes. Experiment with tweaking the two parameters in the file.

If you can't download Free Pascal to compile it, I can try compiling for Win64/Linux64 and post the binaries.

EDIT:- Could use more testing. Bug reports welcome.

I tried 20T-21T on a Linux (ubuntu) 64bit CPU c2q 6600 2.6Ghz

Time 28 min.

sieved to 100G

~3.5M candidates left !!

Should it be that many ??

Lennart

[Oddball]

Originally Posted by Lennart

I tried 20T-21T on a Linux (ubuntu) 64bit CPU c2q 6600 2.6Ghz

Time 28 min.

sieved to 100G

~3.5M candidates left !!

Should it be that many ??

Lennart

There should be 1M candidates left after sieving to 100G. Maybe you sieved to 100M instead?

But even then, sieving 1T to p=100M in half an hour is really fast. One quad core machine could finish the entire k=1-500T range in less than a week!

[Lennart]

Originally Posted by Oddball

There should be 1M candidates left after sieving to 100G. Maybe you sieved to 100M instead?

But even then, sieving 1T to p=100M in half an hour is really fast. One quad core machine could finish the entire k=1-500T range in less than a week!

I used axn's code.

Lennart

[axn]

Originally Posted by Lennart

I used axn's code.

Lennart

That only sieves to 100M. The file can be further sieved using NewPGen.

[Lennart]

Originally Posted by axn

That only sieves to 100M. The file can be further sieved using NewPGen.

Yes I saw that later

Thanks

Lennart

[axn]

Originally Posted by Lennart

Yes I saw that later

Thanks

Lennart

Can you do one more benchmark? Can you double both SieveSize and SmallPrimes and rerun it? That will double the sieve depth to appr 200M. It would be interesting to see the scaling.

[Lennart]

Originally Posted by axn

Can you do one more benchmark? Can you double both SieveSize and SmallPrimes and rerun it? That will double the sieve depth to appr 200M. It would be interesting to see the scaling.

Ok I shall try.

Lennart

EDIT: I have started 20-21T with those changes.

[Lennart]

Originally Posted by axn

Can you do one more benchmark? Can you double both SieveSize and SmallPrimes and rerun it? That will double the sieve depth to appr 200M. It would be interesting to see the scaling.

Ok done to 200e6 33min. 3M candidates left.

smirre2@smirre2-desktop:~/Desktop/tps_pascal$ ./LuckyMinus.pas 1000000 20 21 

smirre2@smirre2-desktop:~/Desktop/tps_pascal$ ./LuckyMinus.pas 1000000 20 21 
Lucky minus n=1000000 k=20000000000025-20999999999985 p<=217645177
2084/2084 = 3037726
smirre2@smirre2-desktop:~/Desktop/tps_pascal$

Lennart

[axn]

Originally Posted by Lennart

Ok done to 200e6 33min. 3M candidates left.

That's actually excellent scaling. The selection of these parameters to optimize the total sieving time is an interesting problem -- probably needing some experimentation. Especially when running single copy vs multiple copies.

It is probably a good idea to increase SmallPrimes much further, depending on how much time NewPGen takes to get it up to 1e9.

[axn]

I am currently trying to compile a Win64 build. But running into some weird runtime error. Need to troubleshoot

[Oddball]

Originally Posted by Historian

Processor: Pentium 4 3.4 GHz
...
NewPGen for "Operation Megabit Twin": estimated to be 80 hours for 1T

I have a similar processor (Pentium 4, 3.2 GHz), and I can confirm that it does take about 80 hours to sieve 1T using NewPGen. With the new sieve, it's expected to take 4-5 hours: 1 hour and 10 minutes using the new sieve to p=100M, and 3-4 hours to use NewPGen to sieve from p=100M to p=100G.