I want to perform a nonlinear least square fit of data points upto 3000. Because the model I provide is huge polynomials with 300 to 400 fitting parameters to be estimated, my mac i7 computer proceeds slowly or not at all proceeding. I just like to know if I can run this fitting calculation in multiple processors. My pc has 4 kernels as shown by mathematica. I want to make use of all of them to perform the fitting procedure. But I donot know how to do this. Is there any specific simple mathematica script I can run so that mathematica runs in all of them in reasonable time limit with least memory. I tried to parallelize the NonlinearModelFit command along with its syntax. It says it can not be parallelized and proceeds in sequencential condition. I tried to use ParallelSubmit with NonlinearModelFit and it optimizes only few fitting parameters leaving the other parameters equal to 1. Can any one tell me how to tackle this problem? I use mathematica 12 version. What about cloud computing. Will this solve the problem. If so, please give me the relevent details.