swapchain to present should be equal to window size

your own swpachains can be any size you want

most of apps use "offscreen rendering" to all the stuff and present everything on swapchain that resize to window

> I’m wondering if it’s possible to just allocate a huge frame buffer/swapchain initially and just adjust the viewport to only show part of the frame in the window

it MAY work on some GPUs/drivers, but some GPU/drivers redraw full "framebuffer" size and size of "draw region"(set by vertex-geometry or viewport) does not mater and redrawing even empty 4k framebuffer its "way too slow" compare to native small size

also allocating large viewport still will use ALOT of VRAM