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2018-04-27, 16:41   #1503
kriesel

"TF79LL86GIMPS96gpu17"
Mar 2017
US midwest

2×2,309 Posts
PRP handling etc

Quote:
 Originally Posted by retina I think it is wrong to selectively have PRP tests appearing in some places and not others. ... As it is now there is a lot of confusion about what happens with PRP tests and how they are counted in various places. ... the fundamental handling of PRP tests still needs to be integrated more thoughtfully. Let's get it fixed.
Yes to all the quoted above.

It's taking a while to get PRP integrated. More visible progress would be appreciated. Work is occurring. There are few manually submitted PRP results, and sometimes they generate issue reports, which tend to generate prompt attempts to fix the issue identified. It's slow going, since not everyone spots or reports issues, and it can be weeks between result records from someone willing to report issues with sufficient detail; resolving one issue can lead to revealing another issue the next time. Issue reports by email with screen shots and copies of the submitted result record seem to work best in my experience. (Reports on a forum thread without details seem to be at the other end of the spectrum.)

There is some utility to distinguishing between PRP and LL primality testing in the various tables. LL is only fully double checked in the sense of a matching residue confirming the calculation went correctly, by another LL check. Quality of LL check varies, because some prime95 runs will include the Jacobi check, while older executable versions will not; gpu runs made by CUDALucas or clLucas will not. A PRP run, on a recent enough version of prime95, or on gpuOwL, confirms another PRP run in the same more thorough sense if the residues match. A Gerbicz-checked PRP may confirm the composite nature of a mersenne number, but yet not confirm the LL residue or run was correct. Matching PRPs confirm each other. Matching LLs confirm each other.

I had the impression from Prime95's participation in the initial discussion of expanding GIMPS to support PRP with Gerbicz check results, that a policy of requiring primality test types to match between a first and second test to declare a mersenne number's primality settled was at least under consideration, and might have been chosen as policy, as a means of promoting the quality of the data in the GIMPS databasae.

There may not be a rule in place, that once one primality test assignment is issued for a given exponent, that others must be of the same type, either by Primenet or manual checkout. Some small subset of exponents having matching PRPs or LLs plus one or two of the other type is ok. This may occur from QA or brute-force benchmarking on software running against known-composite exponents. It's likely to occur with new primes. To frequently have primality type not match between first and second test does not seem efficient. But the resulting residues may have future utility.

Some form of representing PRP in the work distribution map table would be welcome.
Clarity, compactness, and completeness conflict.
I'd like to see twice the frequency of the header lines
Code:
----------=-----=-- | -----=-----=-----=-----=----- | -----=-----=-----=----- | -----=-----=-----=----- |
Exponent Range    | Composite  | Status Unproven  |        Assigned         |        Available        |
Start   Count  P |   F   LL-D | LL   LLERR NO-LL |  TF    P-1   LL   LL-D  |  TF    P-1   LL   LL-D  |
----------=-----=-- | -----=-----=-----=-----=----- | -----=-----=-----=----- | -----=-----=-----=----- 
so that one header was always on screen no matter which portion was scrolled to. Shrinking font size in the browser to get that to be the case with over 110 lines vertically, makes the characters so small they're very difficult to read.

Also, there are no columns for PRP performed or PRP DC or P-1 performed counts or TF performed counts. It's hard to tell in what ranges the various algorithms haven't even been tried yet. The table is wide now, but there's room on my screen and probably many others to widen it further.