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-   -   Reserved for MF - Sequence 4788 (https://www.mersenneforum.org/showthread.php?t=11615)

10metreh 2009-03-24 07:37

[quote=mdettweiler;166441]The next line (2358) has a C92 that survived full ECM. My resources are completely tied up for tonight, so if anyone else wants to do QS on this, go ahead. If nobody's grabbed it by the time I get on tomorrow (probably late morning) I'll do it myself since things should be freed up a bit by then.

The number is:
[code]23815769543009537132187278752799013868767385674615392411879275450950012601757447373080004859[/code][/quote]

I'd like to see this done by this afternoon/early evening (GMT), because this gives me most time to compute more.

mdettweiler 2009-03-24 07:38

[quote=10metreh;166452]I'd like to see this done by this afternoon/early evening (GMT), because this gives me most time to compute more.[/quote]
Okay, no problem. I presume, thus, that you'll do it? (considering that it's 7AM GMT right now)

10metreh 2009-03-24 07:47

[quote=mdettweiler;166453]Okay, no problem. I presume, thus, that you'll do it? (considering that it's 7AM GMT right now)[/quote]

Nope - no computer access for a while. I won't have much time until the weekend to do jobs much larger than C85.

axn 2009-03-24 08:21

Msieve is cranking away on the C92 even as we speak! ETA: 2 hours.

mklasson 2009-03-24 11:22

[QUOTE=mdettweiler;166451]Oh, wait! I just realized what's going on. henryzz, are you by chance using the 64-bit version of gnfs-lasieve4I12e? I'm using the 32-bit version, which of course is about half as fast--so that would explain the discrepancy perfectly. :smile:[/QUOTE]

I'm not so sure about that. The 64-bit version is significantly [b]slower[/b] than the 32-bit version on my system... I don't know why, but I've seen other people report the same problem (which was why I checked and noticed it in the first place).

Maybe comparing yield over a certain range is a more portable way of measuring the poly quality?

axn 2009-03-24 12:30

[QUOTE=mklasson;166476]Maybe comparing yield over a certain range is a more portable way of measuring the poly quality?[/QUOTE]

Without knowing the actual factor base sizes, large prime bounds, etc.., it is an apples to oranges comparison, innit?

mklasson 2009-03-24 12:39

[QUOTE=axn;166481]Without knowing the actual factor base sizes, large prime bounds, etc.., it is an apples to oranges comparison, innit?[/QUOTE]

I'm not suggesting it should be used for anything serious... It just seemed a possibly better idea for them than comparing the sec/rel with different processors.

10metreh 2009-03-24 12:47

[quote=axn;166458]Msieve is cranking away on the C92 even as we speak! ETA: 2 hours.[/quote]

And... (I'm not at home, so I won't be able to do much work on the next iteraton(s))

axn 2009-03-24 12:50

[QUOTE=mklasson;166485]I'm not suggesting it should be used for anything serious... It just seemed a possibly better idea for them than comparing the sec/rel with different processors.[/QUOTE]

Even though I quoted your post specifically, it was intended at the general discussion. The two different speeds posted here for the two different polys didn't have enough supporting information to tell if it is an anomaly or par for the course (quite possible that both are using the default values for factMsieve, but we don't know). I was just trying to highlight that fact :smile:

Anyway, the difference between the two CPUs (3GHz Q6600 (4MB L2) vs 2.2GHz E4500 (1MB L2)) is enough to explain the bulk of the discrepancy.

For proper comparison of two polys, the SOP is to trial sieve at different q-values with the same set of parameters, and look at the sieve speed (which is IMO, better than yield count) for the _same_ processor.

EDIT:- The discussion is getting pretty offtopic. So...

bsquared 2009-03-24 13:08

[quote=mklasson;166476]I'm not so sure about that. The 64-bit version is significantly [B]slower[/B] than the 32-bit version on my system... I don't know why, but I've seen other people report the same problem (which was why I checked and noticed it in the first place).

Maybe comparing yield over a certain range is a more portable way of measuring the poly quality?[/quote]

There are two 64 bit gnfs-lasieve*Ie versions, one with and one without assembly optimizations. The one with is approximatly twice as fast as the one without (and twice as fast as the 32bit version), but AFAIK, is only available on linux.

mklasson 2009-03-24 13:16

[QUOTE=bsquared;166491]There are two 64 bit gnfs-lasieve*Ie versions, one with and one without assembly optimizations. The one with is approximatly twice as fast as the one without (and twice as fast as the 32bit version), but AFAIK, is only available on linux.[/QUOTE]

Ah, what horrible bad luck for me to be running windows then... As usual, inline asm seems to be the culprit. :cry:


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