Hi all, If my understanding is correct, GROMACS parallelization and acceleration page indicates AVX2 SIMD intrinsics can offer a speed boost on a Haswell CPU. I was wondering how much performance gain we can expect from it. In another word, what's the approximate speed increase if we run a simulation with AVX2 SIMD intrinsics on a Haswell CPU (say i7 4770K) than on an Ivy Bridge CPU of the same clock (say i7 3770K) with the current AVX SIMD intrinsics? And is there a timeline for the release of AVX2 SIMD intrinsics?
This information is crucial if we want to assemble a machine with balanced CPU and GPU performance. My current machine has i7 3770K (3.5GHz, stock frequency) and Geforce 650 Ti (768 CUDA cores, 1032MHz). When I ran simulations with rcoulomb=1.0 and rvdw=1.0, I got this at the end of the log file: *Force evaluation time GPU/CPU: 1.762 ms/1.150 ms = 1.531* * * It seems I need a GPU with 50% more CUDA cores. In the best scenario, If AVX2 can give 30% speed boost, and I can successfully overclock 4770K to 4.5GHz, I need 1900 CUDA cores( 130%*(4.5GHz/3.5GHz)*1.531*768 cores) at the same frequency to get balanced CPU and GPU performance. Then I will need a GeForce GTX 780 (2304 CUDA cores at 863MHz, equivalent to 1925 CUDA cores at 1032MHz). Since GROMACS is highly insensitive to memory clock and latency, I hope this naive arithmetic can give a good estimation which graphic card I should purchase. Best Bin -- gmx-users mailing list gmx-users@gromacs.org http://lists.gromacs.org/mailman/listinfo/gmx-users * Please search the archive at http://www.gromacs.org/Support/Mailing_Lists/Search before posting! * Please don't post (un)subscribe requests to the list. Use the www interface or send it to gmx-users-requ...@gromacs.org. * Can't post? Read http://www.gromacs.org/Support/Mailing_Lists
