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Old 2007-12-11, 15:03   #3
P90 years forever!
Prime95's Avatar
Aug 2002
Yeehaw, FL

22×43×47 Posts

Thanks, Alex. Your formula was exactly what I needed. Like I said too much accuracy in curve counting is not critical as the only consequence is you move on to a larger B1 a liitle too early or a little too late - no big deal.

Another ECM puzzle for you: I want to hand out ECM assignments such that I roughly maximize the chance of finding a factor for a given effort. What formula would you use given the quantities total_ecm_effort (the sum of completed B1 values) and N (the Mersenne exponent). Ignore the step function nature of FFT lengths and assume the time it takes to run an ECM curve is proportional to N (log N).

A simpler way to phrase this is: If an exponent has had a total_ecm_effort X, what is the probability the next ECM curve will find a factor (to make life easier, ignore the step nature of assigned B1 values).

Given such a formula I can then use the expected CPU run time to maximize factors found.
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