Factoring vs. Sieving

[Bananaman42]

I run an Intel dual-core at 2 gHz that's on constantly. What I'm trying to figure out, though, is whether it's more productive for me to run Proth tests, sieve, or some combination of the two. Thoughts?

[hhh]

What is most productive for YOU may depend of your definition of productivity; the most productive for the project, though, in terms of eliminated candidates, is to sieve. It should be more than 4 times more effective than Proth tests; and factoring would not even be necessary at the current level, if sieving was finished (i.e. advanced to a point where itself is not efficient anymore).
If you run a 64bit OS, it's even more effective. You may want to try out the BOINC sieving at PrimeGrid.com . H.

[Bananaman42]

Thank you for the information! I guess I'll finish up the Proth tests I'm partway through and switch over to BOINC sieving. Two more questions: Why is sieving more productive for the overall project, and why is it more efficient on a 64 bit OS? Thanks.

[hhh]

The sieve client is bebeficing from optimized code for 64 bit systems. And as you may know, by sieving, we try to find factors for numbers we would else have to rum Proth tests on. It happens that finding factors is much faster than doing the tests. Yet, we will never find any primes just by sieving, so, at some point, we need to start the Proth tests. The idea is to do that when we have eliminated all the candidates we could by sieving.

There is plenty of information on the forum; reading your way through will take some time, but be a rewarding experience. H.

[Slatz]

just curious what the optimal sieve depth is?

Slatz

[hhh]

I am doing some research on this topic these days. I suppose it to be around 50P, more probably 100P. Still much work to do, but Primegrid is advancing fast. When I manage to calculate the exact figures, I will post them of course. H.

[Bananaman42]

Also from curiosity, how often are the sieve results merged to remove candidates for proth tests?

Thanks,
Bananaman

[vjs]

As soon as the user submits them they are rempved from the ques.

It takes a while to remove them from the dat but that's not really important anymore.