highest testable LL exponent

[joblack]

Hi,


I have finished my 100M LL testing and so I am browsing through the map for a new challenge.


https://www.mersenne.org/primenet/


The highest possible numbers are higher than 999000000

but in Prime95 Test it says it needs between 5 and 922600000.

So what's the highest possible prime number I can savely test with Prime95 Windows executable?

Is there a page to play around with possible values?

[Prime95]

AVX-512 CPUs could go over 1 billion

[joblack]

Originally Posted by Prime95

AVX-512 CPUs could go over 1 billion

Okay but Prime95 does say


Prime95 Test it says it needs between 5 and 922600000


if I press 'Test'?


I have a Ryzen 3700x with Windows 10.

[hansl]

Originally Posted by joblack

Okay but Prime95 does say


Prime95 Test it says it needs between 5 and 922600000


if I press 'Test'?


I have a Ryzen 3700x with Windows 10.

So get the largest prime less than 922600000:
(PARI/GP)

? precprime(922600000)
%1 = 922599973

Ryzen 3700x does not have AVX-512 by the way.

[joblack]

Originally Posted by hansl

So get the largest prime less than 922600000:
(PARI/GP)

? precprime(922600000)
%1 = 922599973

Ryzen 3700x does not have AVX-512 by the way.

Yeah you're right. No AVX-512. Will check it out. Thanks.

[ET_]

Originally Posted by Prime95

AVX-512 CPUs could go over 1 billion

Is the limit defined on any readme or undoc? I could not find it...

[Prime95]

From gwnum.h:

#define MAX_PRIME_AVX512 1169000000L /* AVX-512 bit limit */

[kriesel]

Switching to CUDALucas, gpuowl, or Mlucas allows higher exponents, up to 2, 3 or 4 billion. But it is not advisable to run such extreme cases, because:
CUDALucas lacks certain error detection features necessary for such large/long runs;
run times will be very long, likely longer than hardware lifetime;
there is no established server to which to report the computation result of a primality test for an exponent above one billion, if one was reached.