factor and factorint performances

Hi everybody,

Playing with factor and factorint functions, I was amazed at their 
performances (compared to other Math libraries), until I tried to 
factorize 2^1003-1.
After more than 11 hours, no result ...
So I tried this Web tool 
(https://www.dcode.fr/prime-factors-decomposition in English, 
https://www.dcode.fr/decomposition-nombres-premiers in French) and got a 
result in ... 2.25 seconds!!!!
Unless they use a supercalculator (and I don't think so), their 
algorithm is very, very efficient.
Is it possible to get the same performance using PariGP? In a previous 
message, Bill said that it could be possible to skip the primality test 
with factor.

The reason PARI is slow is that it does a primality test each time it 
finds a factor. Since the number is large with lots of factors, then it 
takes a long time. (about 90s for each factor). So it should finish in 
about 54 hours. If we expected that the number do not have prime factors 
larger than some bounds, we could just skip the primality test.

Could this be a solution? How would you do that?

TIA for your help.

-- 
Jean-Luc Arnaud