2020-01-04, 00:57 #31 ATH Einyen     Dec 2003 Denmark 22·757 Posts Thanks, it worked. I tested it in an EC2 instance with 1 core / 2 threads (Xeon Cascadelake) on a 402 bit prime number: 160 curves at B1=1,000,000: GMP-ECM: 300.6 sec AVX-ECM 1 thread: 179.5 sec AVX-ECM 2 threads: 144.8 sec I created a 402 bit composite number with a 30 digit (97 bit) factor and tested it 10 times with B1=1,000,000 (35 digit level) to see how fast the factor was found with GMP-ECM and AVX-ECM: Code: GMP-ECM AVX-ECM curve 23 curves 0-15 curve 34 curves 16-31 curve 48 curves 32-47 curve 81 curves 48-63 (found twice) curve 89 curves 64-79 curve 129 curves 144-159 curve 135 curves 144-159 curve 168 curves 160-175 (found twice) curve 195 curves 384-399 curve 264 curves 416-431 So based on the speed from the first test GMP-ECM found the factor 10 times in 2191 seconds and AVX-ECM found the factor 10 (12) times in 1419 seconds. I took the 12 sigmas values for which AVX-ECM found the factor and tested in GMP-ECM, and it found the factor as well with all the 12 sigmas. Last fiddled with by ATH on 2020-01-04 at 01:06