Hello @hassan.h.n.91, We don’t provide any particular hardware suggestion because the requirement would be different based on the project size and output you are looking to generate. Giving the time estimation would be difficult for anyone because it won’t be accurate. However, I would suggest you to use PIX4Dmatic which is designed to process larger projects without crashing.
We do not have specific hardware recommendations but there are several resources that I can send you which will help answer many of your questions. You can find some links below.
Hardware Components Usage when processing with Pix4D
Pix4D Computer hardware community benchmark
Puget Systems have also performed their own investigations which I will share with you HERE. Since this is not Pix4D affiliated we cannot verify the results they present but you may find it useful all the same.