Next Available Range

[Matt]

The manual reservation system has now reached the end of it's current segment of work at 13,000,000. PrimeGrid has reserved all of the ranges from there to 100,000,000, so unless we can have some of that area back from PrimeGrid then I would suggest that jumping that far ahead is a bit of a waste of time - correct?

I would appreciate if a range could be nicked back from PrimeGrid ASAP please?

Also it should be noted that people took up the reservations from 12.8 - 12.9 in a very short space of time (about 2 weeks). Obviously several of these ranges are still in progress but I would appreciate someone else's input on the situation please?

[hhh]

I guess you can just claim some range you want and notify PG; they are nice people and very comprehensive. Just take 50P-51P, for instance; PG should reach that level in half a year or so. H.

[Matt]

Have liased with Joe O and agreed that jumping to 100P is not a problem.

[opyrt]

Just thought I'd mention that moving from 13P to 100P seems to have increased the memory usage per instance of sr2sieve.exe from 80MB to 200MB.

Don't know if others have seen the same, but it might be smart having this in the back of your heads before starting 8 instances of sr2sieve.exe on your dual quad core. :-)

[Death]

how about some double check?

[opyrt]

how about some double check?

I'm no guru when it comes to this, but in my mind it does not seem worth it to double check sieving. It would cost alot of CPU time and save very, very, very little CPU time.

In a way, you could say that the PRP tests are double checking the sieving effort anyways.

And from what I understand, all reported factors are validated upon reporting, so it will not happen that a kn-pair is falsely excluded. A double check sieve would then only be useful for finding factors that was lost the first time around, and I doubt there are many.

[Razor_FX_II]

Just thought I'd mention that moving from 13P to 100P seems to have increased the memory usage per instance of sr2sieve.exe from 80MB to 200MB.

Don't know if others have seen the same, but it might be smart having this in the back of your heads before starting 8 instances of sr2sieve.exe on your dual quad core. :-)

With the amount of memory in a modern day computer I don't see where this is a problem.
Most computers have at least 2gig if not 4-8gig in them from conception.
The introduction of Windows 7 and the availability of 6 ram slot on new I7 motherboards lets these ranges easily fall within the range of any modern day computer.

[opyrt]

With the amount of memory in a modern day computer I don't see where this is a problem.
Most computers have at least 2gig if not 4-8gig in them from conception.
The introduction of Windows 7 and the availability of 6 ram slot on new I7 motherboards lets these ranges easily fall within the range of any modern day computer.

I did not mean in any way that this is a problem. I just wanted to share a fact that is "nice to know". :-)

[Nasdaq]

Have liased with Joe O and agreed that jumping to 100P is not a problem.

You guys are nuts - there's no point in sieving at that high level, and you'll break even at best. This is getting extremely close to the point where the average time it takes to find a factor is longer than the time to finish a PRP test.

Unlike GIMPS, we're not trying to find all the primes in the range being sieved. A prime for one of the six k's at 17M, for example, means that all the factors for that k above 17M are now useless, since that k is eliminated. When you take this into account, the optimal sieve depth will be lower: around 50-75P.

[opyrt]

You guys are nuts - there's no point in sieving at that high level, and you'll break even at best. This is getting extremely close to the point where the average time it takes to find a factor is longer than the time to finish a PRP test.

From what I see on my testrange above 100P this seems correct. Having 8 cores running for 3 days without a result feels demoralizing.

Matt: Any chance we could get a lower range back from PrimeGrid? In that way we could actually contribute. ;-)

[runesk]

From what I see on my testrange above 100P this seems correct. Having 8 cores running for 3 days without a result feels demoralizing.

Matt: Any chance we could get a lower range back from PrimeGrid? In that way we could actually contribute. ;-)

I've done my last manual sieve range above 100P. Crunching all weekend without a hint of a factor gives me no joy.

My thoughts is that if you want to continue supporting manual sieveing, you should get back some of the range received by PrimeGrid. The other solution is to only support PrimeGrid... (and then you should be removed from DC-Vault as well). I might join PrimeGrid, but at the moment, my focus is non-boinc, and I get some strange satisfaction doing just that (some might consider this some kind of insanity, I'm sure)...

.R