However 5x and 6x modes were deliberately disabled. I think this was because of their exhaustive video memory usage. While I see no problem with turning them on, you should convince Graf with this change.
Samuel Turveywill wrote:Would it be possible to add with a warning on the "Modern" GZDoom?
That sounds like a good idea. Perhaps, an even better approach would be to check how much VRAM is available, and if it's sufficient enough, the modes are enabled. And if there isn't enough VRAM available in the check, the modes are disabled.
It would depend on more than just how much VRAM is available, but also the textures used by a given map. Maps that use a few small textures won't be as much of a problem compared to maps that use a lot of large textures, for instance. And the latter would be more of a problem than a map that uses a lot of small textures. I don't think the engine will know how much VRAM will be needed until it's needed.
Worse, OpenGL does not provide any useful facilities to assess the memory needs. It will just resort to system memory and result in texture thrashing, making the game slow.
A 6x scaled texture consumes 36x the VRAM of the unscaled variant. A 4x scaled texture only 16x. And here the law of diminishing returns strikes mercilessly. It's simply not worth it, dealing with massively increased texture creation times and massively increased VRAM usage for some minor visual improvement.
To give you an idea: A really resource intensive map like ZDCMP2 needs 4GB of VRAM to handle 4x upscaling for everything. To do 6x it'd require 10 GB! Does that even exist?
If it helps at all, If 5x or 6x was enabled on a Dev build i'd be willing to run some benchmarks or tests with the 1080TI for you guys with whatever settings required.