Quote:
Originally Posted by cheesehead
The efficiency of each choice is proportional to the ratio (chance of finding a factor)/(time to find a factor), so that ratio calculation is the one I use in the following: Prime95 will prefer combination X because 1.0%/10 (.010/10) is greater than 1.3%/15 (.013/15) or 1.5%/16 (.015/16).

No
Quote:
Originally Posted by http://www.mersenne.org/math.htm
So how does GIMPS intelligently choose B1 and B2? We use a variation of the formula used in trial factoring. We must maximize:
chance_of_finding_factor * 2 * primality_test_cost  factoring_cost

You cannot define efficiency of P1 without considering the cost of an LL test.