Hi Jason, I am also interested in this issue. My project involves MPFR which is built on top of GMP. I recently started optimizing the performance of MPFR and GMP using the Intel architecture. The learning curve of the whole set of Intel tools is quite steep so I don't have much progress yet. What I know is that Intel has reimplemented GMP in their MKL library. So I guess I will try compiling MPFR on top of the Intel version of GMP and see how it goes. The next step might be to parallelize the MPFR routines as what you've suggested... Could you please give some pointers on how to do these types of parallelization? Thanks -M <div>On 1/11/07, Jason Martin <<a href="mailto:jason.worth.martin@gmail.com"> jason.worth.martin@gmail.com</a>> wrote:<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">Hi All, Out of curiosity, I recently tried a naive multi-threaded multiplication scheme (using pthreads) and got a speed-up of about 25% for extremely large operands (over 2000 limbs).  I was just using simple "textbook" style multiplication (break the larger operand in half, do two multiplies using mpn_mul, then shift/add back together). I got similar results on a Woodcrest running OS X and a dual core Opteron running Linux. I suspect that a quad-core CPU in which all the cores share the L2 cache could really benifit from a Karatsuba-style multi-threaded multiply since the three multiplies could run in parallel without having to go off-chip for memory accesses. Is anyone working on this already?  Does anyone care? --jason -- ----------------------------------------------------------- Jason Worth Martin Asst. Prof. of Mathematics James Madison University <a href="http://www.math.jmu.edu/~martin">http://www.math.jmu.edu/~martin </a> phone: (+1) 540-568-5101 fax: (+1) 540-568-6857 "Ever my heart rises as we draw near the mountains. There is good rock here." -- Gimli, son of Gloin _______________________________________________ gmp-discuss mailing list <a href="mailto:gmp-discuss@swox.com">gmp-discuss@swox.com</a> <a href="https://gmplib.org/mailman/listinfo/gmp-discuss">https://gmplib.org/mailman/listinfo/gmp-discuss</a> </blockquote></div>