> It doesn't have to happen as fast as possible, and can be throttled through e.g. v-sync or lower-than-max FPS targets or turning on and off specific display f

> It doesn't have to happen as fast as possible, and can be throttled through e.g. v-sync or lower-than-max FPS targets or turning on and off specific display features that might tax the GPU more (e.g. if shaders get involved, alpha blending is used, etc.). Exactly. E.g if you want to render as fast as possible, the logical way of doing it is to keep track of how many lines have been output (the easiest, but not necessarily most efficient, way is to render to a scrollback buffer) and then separately, synced to v-sync if you prefer, start rendering from what is at the top of the virtual text-version of the screen when the rendering starts a new frame. Do this in two threads, and you can then render to the bitmap at whatever FPS you can handle, while you can let the app running in the terminal output text as fast as it can produce it: If the text-output thread manages to add more than one line to the end of the buffer per frame rendered to the bitmap, your output will just scroll more than one line per frame. You've then decoupled the decision of the FPS necessary from how fast the app you're running can output text, and frankly, your FPS needs to dip fairly low before that looks janky.