HI
I am using Zwift on a macbook which is a few years old and towards your lower end of the system requirements.
I have only started using Zwift but on the few rides that I have done it keeps freezing coming up to the turns or it seems if there is a lot of other riders around. over my last ride I had a recorded time of 54 mins but i had started my fitbit timer on this ride and had been pedaling 10 mins longer than my saved time.
Would this be a problem with zwift or my laptop. I did not loose internet connection at anytime. the only option to upgrade spec on my macbook is the memory to 8GB from 4 but not sure how much of a difference this will make?