Man for $600 you could build a PC with all brand new modern parts that will run Zwift in 4K60. Don’t buy this crap, please.
Here, buy one of these: HP ProDesk 400 G1 MT Desktop Computer i3-4130, 4GB, 500GB, W10P, Restored | eBay
Plop another 4GB stick of RAM, a 128GB SSD (replace the HDD) and a GTX 1050 Ti in it. All done for well under $200 and it will do Zwift in Ultra profile, at 60fps and 1440p resolution - same rules about being CPU bound apply. Job done.