I ran the model I proposed with rstan and got a converged solution after fitting 4 chains using all cores on my laptop. As it takes a long time to finish running one specific condition and I have many conditions to run, I can understand the effect sample size will change because it was combined effect sample size from all the chains. Will the mean, mean_se change, which are my focus of interest? Is it legitimate to run 1 chain only after having obtained a converge solution?
To make it clear, this is more about a concern on CPU and memory usage. I thought to myself when I only run one chain, it will use less computing resource on my PC, whereas when I run 4 chains, it definitely uses more computer resources than only 1 chain. I may be wrong. :-)
Thank you very much.