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Old 2020-11-27, 18:20   #15
kriesel's Avatar
Mar 2017
US midwest

7×701 Posts

Just to be clear, all functional GIMPS software contributions and their authors are welcome and respected. Cllucas used to be the best primality testing software for Mersennes on OpenCL. Eventually it was eclipsed by Gpuowl. I had written a combined TF and LL test program for x86 on DOS, doing it all integer and without the benefit of some number theory understanding; trial long division and grammar school squaring, in Fortran and then C. Single threaded, but didn't matter way back then when dual processor systems were rare. The run time scaling was absolutely dreadful (higher than cube of exponent), and made clear that better algorithms and better implementation were both required to have any chance. I learned of prime95 and its fft based multiplication in mid 1996, after beginning to implement Karatsuba. It didn't take long to decide to switch to George's far superior program.

Last fiddled with by kriesel on 2020-11-27 at 18:26
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