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Old 2020-06-28, 13:35   #4
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Jun 2003

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Originally Posted by windowfrog View Post
So the PRP-CF test would try to find co-factors of an exponent that’s already a known composite?
Not quite. PRP-CF tests the cofactor to see if it is (probable) prime, i.e. whether the Mersenne number is fully-factored.
Just to clarify, if the mersenne number M(p) has a factor f, then the cofactor is M(p)/f.

Originally Posted by windowfrog View Post
For the P-1 test, how much RAM is needed? If I have 16 GB on my machine, is 8 GB enough?
Give it as much as you can spare without compromising the usability of the system. 12GB out of the 16GB should be safe to give. But even 8GB is pretty good.

Originally Posted by windowfrog View Post
If the P-1 test only finds factors/cofactors, would it make sense to run PRP tests on the really big numbers on the newer laptop, while searching for cofactors on the old?
Sure. PRP-CF & ECM have small runtimes, and comparatively less memory requirement. P-1 has small runtime, but during stage 2, benefits from lots of memory. Beefier hardware can do doublechecks or even first time tests. For the DC/FC, and even P-1, use a multi-threaded configuration, where all your cores work on a single test.
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