Hello,
I am using texture atlases in my game. Until now I only used 2048x2048 or lower.
Is there a Problem with older GFX Cards (DirectX9 is Minimum anyway), or Notebook GFX (onboard) Cards with a 4096x4096 texture Atlas?
Could the perfomance be lower? Would it matter on PS4 if we may target it later (unsure right now)?
Thanks a lot! 
AFAIK, older GPU’s don’t support bigger textures. Which means that either they won’t load or you’ll get a crash by trying to force it (not sure how Unity handles it). Having as many textures you can on the same atlas would help with performance (assuming they’re being batched correctly), and I’m sure that the current generation consoles can support 4096x4096 (you’d have to check and make sure, only assuming).
But for better compatibility across a wide range of older hardware (unless you don’t want to support them), it’s best to stick with lower res atlases.
Almost all current hardware (phones included) supports at least 8192x8192, the maximum Unity itself can support. 4K textures should not be a problem unless you’re targeting extremely old hardware. PS4 can handle 4K textures without breaking a sweat.
As always, be sure to profile on your target platform to see if it has performance implications for your particular game.
4096 textures were a problem on some iOS/Android phones up until “not that long ago”. It’s definitely worth giving serious thought/research to. I still stick to 2048 textures as I got stung on my game Coldfire Keep which was all 4096 and wouldn’t run on some devices that I was wanting it to run on.
Changing your atlases to 2048 from 4096 at the end of the project can be a huge pain in the ass.
Thanks for the info!
I am thinking of PC and PS4 only. I have read a lot and it is always different.
Most say grahphic Cards since DX9 compablity (or a later Version of dx 9 compability) Support it, and all newer Cards.
My game Needs a good graphic Card I would say nvidia 960 up, so I guess I can Switch to 4096 without a Problem in my desired custormer target area…
Thanks!