Nvidia dominates the top 10 in the GPU performance charts at 4K Ultra for Zwift. Using the Zwiftalizer data, Jupyer notebook, Pandas and Matplotlib, this post shows how to get the top 10 GPUs from the 4K Ultra category that have a minimum frame rate of 60 FPS, then rank them to get the top performers. Nvidia takes the lead. AMD Vega 64 and RX 580 can do 4K Ultra but did not make the top 10 because they did not meet the high bar of a 60 FPS minimum.
In response to a question about the Zwift graphics engine choices on Reddit, October 30th 2019, game creator John Mayfield had this to say:
Zwift is tailored to lower end hardware, and we’re not shooting for Crysis 3 level graphics because almost none of our users a) care and b) have a machine that can render 100+ riders ontop of a very detailed world.
We optimize for the 90% rather than the 10%.
A great question that often comes up is, what FPS should I expect to get with a GPU that can do 1080 resolution with the High profile? Unlike resolution, profile is the level of detail and effects in the scene and can not be chosen by the user.
45 FPS is the answer, according to the data.
For 1080 resolution with the basic profile, the answer is 35
For 1080 resolution with the ultra profile, the answer is 60