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Old 2003-03-07, 17:00   #3
ewmayer
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Sep 2002
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Default Re: Glucas/Mlucas errors...

[quote="Xyzzy"]
Here is the output from Mlucas...

[code:1][Xyzzy:~/Desktop/Mlucas] mvang% ./Mlucas
looking for worktodo.ini file...
no worktodo.ini file found...switching to interactive mode.
Enter exponent, FFT length in K (set K = 0 for default FFT length) >9490001,480
Enter 'y' to run a self-test, <return> for a full LL test >y
Enter number of iterations for timing test>
100
Enter index of radix set to be used for the FFT:
(See file fft_radix.txt for a list of available choices; enter -1 to get the default) >-1
Enter 'y' to enable per-iteration error checking, <return> for no error checking >y
p is prime...proceeding with Lucas-Lehmer test...
M( 9490001 ): using FFT length 480K = 491520 8-byte floats.
this gives an average 19.3074564615885 bits per digit
INFO: Using real* 8 for FFT sincos and DWT weights tables inits.
WARN: radix set -1 not available - using defaults.
Using complex FFT radices 15 16 32 32
M 9490001 Roundoff warning on iteration 24 maxerr = 0.406250000000
M 9490001 Roundoff warning on iteration 25 maxerr = 0.500000000000
FATAL ERROR...Halting execution.
STOP
[/code:1]

Apparently I was overly aggressive in setting the maximum exponent for the 480K FFT length - try using 512K instead. If you're planning a full test of an exponent in this range, you can override the program's default FFT length by starting the run in interactive mode as above and specifying the appropriate FFT length, then after the program gets to the first checkpoint, kill the run and restart from the worktodo.ini file - the run will continue with the manually set FFT length, but will write outputs to the pXXX.stat file, as it normally does for batch mode runs.

As far as your 4608K run is concerned, I'm not sure how I settled on 87.7M as the max exponent for that FFT length, but it's much too large - my current version of the code lists 83.76M as pmax for 4608K.

Cheers,
-Ernst
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