Prime95 defaults to proof=8 for PRP-CF tests even though I have a very large disk space allocated

[ATH]

Originally Posted by Prime95

Over 414.2M the proof power goes to 11.

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[kruoli]

Originally Posted by ATH

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XKCD 670.

Wouldn't it be nice if the comic was embedded? But I guess that's problematic from a copyright view?

[kriesel]

Originally Posted by Prime95

414.2M+ = 11

Presumably that + is for up to 1G mersenne.org limit, or 1169M max of AVX512 prime95. Or would it apply all the way up to say OBD (3322M)? Is the optimal proof power an output of a straightforward function or does it require empirical testing to determine?

[Prime95]

Originally Posted by kriesel

Presumably that + is for up to 1G mersenne.org limit, or 1169M max of AVX512 prime95. Or would it apply all the way up to say OBD (3322M)? Is the optimal proof power an output of a straightforward function or does it require empirical testing to determine?

It's a simple formula, I've already forgotten it. Shouldn't be hard to re-derive.

I didn't worry about OBD, it looks like the next transition will be near 1600M.

[kriesel]

Looks like about every 2 bits on fft length is +1 on proof power. So (extrapolating in Mlucas fft lengths) that would imply power 12 would be sufficient to ~6.2G, ~1.87 Gdigit, not something of concern for decades or centuries.

[retina]

Originally Posted by kruoli

Wouldn't it be nice if the comic was embedded? But I guess that's problematic from a copyright view?

Originally Posted by XKCD

This means you're free to copy and share these comics

I don't see any problem.

https://xkcd.com/license.html