Hello, everybody. Myself Anuj Kaushik, a research scholar at IIIT Allahabad, India.
I’ve a computer with 128 GB RAM, 40 cores, CentOS. I am using matlab for a job, which basically does addition, multiplication, fft and ifft of 2D matrices (4096x4096).
First I used for loop (sequentially). I saw that all the cores were busy/working. Why? I expected that only one core would be busy.
Then I used parfor loop (parallel computing). As expected 40 cores were running.
The time taken by my program for 5 different configurations in case of parallel computing were 747s, 801s, 788s, 836s, 1156s and 24s, 22s, 23s, 24s, 28s for serial computing, respectively. My question is when it is performing in parallel computation, why still taking so much time?