[QUOTE=GP2;496024]
and for both type-1 and type-5, the residues, as calculated by mprime, change as we add known factors to the factor string.

[/QUOTE]

At least those type 1 results are good, for example:
[CODE]
(09:56) gp > N=(3^2131-1)/2/459589675789;
(09:56) gp > lift(Mod(5,N)^(N-1))%(2^64)
%2 = 3902796578086613427
(09:56) gp >
[/CODE]

[QUOTE=R. Gerbicz;496055]At least those type 1 results are good, for example:
[CODE]
(09:56) gp > N=(3^2131-1)/2/459589675789;
(09:56) gp > lift(Mod(5,N)^(N-1))%(2^64)
%2 = 3902796578086613427
(09:56) gp >
[/CODE][/QUOTE]

After I looked at it again and fixed my code, it seems that for repunit base b=3, it is sufficient just to use type-1 residues with PRP base 2.

I was able to use your cofactor-compositeness method and calculated modular inverse to "rediscover" the PRP cofactor exponents p = 2113, 2131, 2141, 2203, 2213, 2417, 2531, 2539, 2699, 4967, 6961, 7577, 8741, 17477, 24697, 26849, 58403.

That was using the limited selection of factors of 3^p − 1 available on FactorDB: only factored to very limited bit depth and only up to p = 100k. Maybe mfaktc can be adapted to find more factors of this form.

I'm not sure about negative bases though. I know that for b = −2 Wagstaff numbers a type-5 residue is calculated, it seems to be a special case. Maybe there might still be an issue for negative bases other than b = −2, especially if the denominator (b + 1) is an even number. I'll look at that later. But I guess for positive bases the type-5 issue doesn't matter.

[QUOTE=GP2;496091]
I'm not sure about negative bases though. I know that for b = −2 Wagstaff numbers a type-5 residue is calculated, it seems to be a special case. Maybe there might still be an issue for negative bases other than b = −2, especially if the denominator (b + 1) is an even number. I'll look at that later. But I guess for positive bases the type-5 issue doesn't matter.[/QUOTE]

Doing (say) a Fermat prp test for base=-b is equivalent to a test to base=b. The generalization of this is that the good bases form a group in Z_N; this is the reason why we use (distinct small) prime bases in general.

A quick question about [I]Prime95[/I]. From [I]undoc.txt[/I]:

[QUOTE]You can control the maximum prime.log file size. The default is 2MB. Add
this line to prime.txt to change the default:
MaxLogFileSize=n[/QUOTE]How do you specify a size for this? Is it in "K" or "M" or some other way?

[QUOTE=storm5510;496685]A quick question about [I]Prime95[/I]. From [I]undoc.txt[/I]:

How do you specify a size for this? Is it in "K" or "M" or some other way?[/QUOTE]

I think it is in bytes.

I think theres a bug in prime95 on latest Windows 10 17763.


Just stress testing,
Min FFT 51200, max FFT 51200
FFT in place unchecked
RAM to test 13926 MB
Time for each test 5 min


Always within a couple minutes prime95 will just quit to desktop, sometimes flickering the screen, bugging Windows 10 color theme around the edge of windows, requiring me to click any color in settings, then pick my (or auto) color again to clear it. Every time, every system, overclocked, stock, underclocked. Back to previous Windows 10 version, doesnt happen..


It also appears to load an abnormally amount of low RAM when its clearly available. Using FMA3 on 8700k.

Maybe it's a bug in Windows 10 17763. Which piece of software changed, after all?

[QUOTE=Yuno;497165]...Always within a couple minutes prime95 will just quit to desktop, sometimes flickering the screen, bugging Windows 10 color theme around the edge of windows, requiring me to click any color in settings, then pick my (or auto) color again to clear it. Every time, every system, overclocked, stock, underclocked. Back to previous Windows 10 version, doesnt happen..[/QUOTE]

It sounds to me like some type of video driver issue. There is an option in there somewhere that prevents Automatic Updates from downloading hardware drivers. It did that on me once and everything went wacko. Even so, this is still very strange behavior for [I]Prime95[/I].

[QUOTE=kladner]Maybe it's a bug in Windows 10 17763. Which piece of software changed, after all?[/QUOTE]

An excellent point. If ever there was a piece of software in a constant state of flux, it is Windows 10.

This is a subject which might find better detail in the [U]Hardware[/U] forum.

feature request or not :)
 

As all you know I extreme like Prime95, and do all PRP testing with him. Since Mark make "new" type of twinsieve I have now interesting situation.
I have two workers , both have two cores ( on quad CPU)
One worker do PRP=1574,3,1778899,1 and second worker do PRP=1574,3,1778899,-1
Since both worker do candidates i same time, I got this error



[QUOTE][Worker #2 Oct 5 11:51:06] Error reading intermediate file: p1574_1778899
[Worker #2 Oct 5 11:51:06] Renaming p1574_1778899 to p1574_1778899.bad1
[Worker #2 Oct 5 11:51:06] All intermediate files bad. Temporarily abandoning work unit.[/QUOTE]


I search on Google and may say it is computer problem: but in my case is not: problem is that intermediate file for both files called same , so that is true reason


So question- request, can intermediate file for +1 has P in name , and intermediate file for -1 has N in name: so prime95 know what intermediate file is for what candidate?

[QUOTE=pepi37;497451]As all you know I extreme like Prime95, and do all PRP testing with him. Since Mark make "new" type of twinsieve I have now interesting situation.
I have two workers , both have two cores ( on quad CPU)
One worker do PRP=1574,3,1778899,1 and second worker do PRP=1574,3,1778899,-1
[/QUOTE]

My free (almost) 2x speedup tip: do only the k*3^n+1 prime tests, and if that is prime then later on or immediately run the k*3^n-1 prp test (which you can also verify it with a true primality test because the factorization of q+1 is trivial).

ps. but why are you using base=3? Quite unusual, also blocks my fast error checking.

[QUOTE=pepi37;497451]
One worker do PRP=1574,3,1778899,1 and second worker do PRP=1574,3,1778899,-1
Since both worker do candidates i same time, I got this error [/QUOTE]

I think the two tests are using the same save file name. Not good.

If you must do these two tests at the same time, run two different instances of prime95 in two different directories. One instance does the +1 candidates and the other instance does the -1 candidates.