@ralph, sry for asking, i know ur busy. Sice the native resolution is 2160X1080 for cv1, why would i choose a different resolution in game? Would that be a waste of resources or would that cause a visible difference?
The way this works with direct mode is a bit different. What counts is the per eye resolution (1080×1200) and you also have to factor in the lens distortion correction which reduces resolution in the center and thus requires games to be rendered at a slightly higher res to get the best possible quality.
The best possible resolutions are the resolutions listed in the “Custom Resolutions” section of the vorpX help or alternatively in this post.
If you let vorpX do its job instead of trying to do a better one yourself, for many games you can simply select a preferred quality in the vorpX menu after adding the custom resolutions to your PC. vorpX will then automatically set the best resolution for that game that fits your selected quality. vorpX can do that for almost 150 games now.