Why doesn't DSR allow for 8k resolutions?

[magellan]

Title says it all, I've read that Nvidia's DSR only allows for 4x whatever the physical resolution of the monitor is, so for a 1080p display you can only get 4k (3840x2160) and for a 1440p you can get 5120, but why? Why not allow all the way up to 8k for a 1080p display?

 

[mackerel]

I'd guess they implemented optimisations for up to 2x linear scaling, and left it at that.

Have to wonder if there is any realistic use case for 8k rendering on 1080p display. Testing 8k when you don't have a display? 8k users probably rely on upscaling to get there in a usable state.