More than one B2 bound per kn-pair?

[jasong]

I was over at Mersenne forum asking about Prime95? Apparently, you can keep a P-1 Stage 1 file, and re-use it with different Stage 2 bounds.

I was wondering(assuming we're already keeping up with first, which might not be true) if we might find more factors, in a given amount of time, if we try more than one B2 value.

When I do things on my Pentium-D, with B1=120,000, and B2=1,700,000, Stage 1 takes 3hrs10min, and Stage 2 takes 2hrs15min.

[Joe O]

Would you do me a favour and try a run with 1800000 and report the times.
Thanks.

[glennpat]

Here are my results:

Intel dual core 6600 at 2.40Ghz with 2GB system memory.
Prime95 available memory set to 1 GB.

With B1=120,000 and B2=1,800,000, Stage 1 takes 1hr 53mins, and Stage 2 takes 1hr 32mins.
With B1=120,000 and B2=1,700,000, Stage 1 takes 1hr 53mins, and Stage 2 takes 1hr 26mins

[jasong]

testing now, when I get up in the morning and remember, I'll post.

[jasong]

A few seconds less than 2hrs42min.

That's just for Stage 2.

[Joe O]

Gentlemen,
Based on your timings, I think that we should increase B2 to at least 1,800,000. If you would try timings at 1,850,000 and 1,900,000 we could use that information.
The goal is to have Stage2 timings equal to Stage1, or at least very close.

[glennpat]

Here are my results:

Intel dual core 6600 at 2.40Ghz with 2GB system memory.
Prime95 available memory set to 1 GB.

With B1=120,000 and B2=1,850,000, Stage 1 takes 1hr 53mins, and Stage 2 takes 1hr 35mins.
With B1=120,000 and B2=1,900,000, Stage 1 takes 1hr 53mins, and Stage 2 takes 1hr 35mins

Another one with B2=1,900,000 and stage 2 was 37 seconds different then the other one with the same B2. Looks like the time for B2 at 1,850,000 and 1,900,000 are about the same.