I'm playing Dark Souls 3 and I cannot achieve stable 1080@60fps. As a fix I'm trying to play at a lower resolution and use the upscale to get 1080p back. The problem is that I only can do this with 1600 x 900 and 1280 x 720. I don't need 1600 x 900, 1776 x 1000 would be better since it's closer to 1080p, but the upscale option won't work with it. Since 1776 x 1000 is 16:9, I think it should work.
What can I do to get the 1776 x 1000 upscaled to 1080?
MSI R9 380 2GB OC