The Vulkan API provides a significant boost in performance
In certain situations, Vulkan API can decrease the overall image quality
Vulkan API in its current implementation is not better than running OpenGL.
No doubt the Vulkan mode provides a significant FPS/smoothness increase. Where I was getting 30-40 FPS over crowded areas like LAX, Vulkan API can keep it will over the 4k 60fps threshold.
HOWEVER: I did encounter a massive drawback, and I hope it is merely related to beta testing, but if you have 8gbs of VRAM, you will not be able to run maximum object settings in crowded places without the ground textures/buildings looking like it reverted to Xplane 9.
The way the new API handles texture loading is voodoo magic to me, but essentially it loads the textures onto the GPU, filling up your VRAM for smoother flying. Sounds great, works great too as long you are in relatively open areas. Flying over big cities or crowded areas brings on the problems. As you fly, the game manages how much VRAM is currently being used. If the game requests more VRAM than you have available, it lowers the quality (resolution) of the textures to fit the available amount. If you look in the Log.txt you will see lines that tell you something like:
0:03:35.388 E/TEX: Target scale moved to 2.000000
The target scale goes from like 2 to 16. 16 being the highest I believe.
So the problem is the game runs smoother and faster, but you cannot raise the settings to take advantage of the newly found headroom because you are hard limited to your VRAM amount. For the 1% of people that own 2080ti’s with 11gb of VRAM, you may not notice this. But for me with 8GB, I may run 20-30fps slower on OGL, but the image is vastly improved. I can run High (HDR) effects, Maximum objects and get about 40FPS over a big city and look great in OGL, but in Vulkan I’ll get 60+ FPS but the texture quality is greatly reduced.
The solution: Limit objects to High if you have 8gb of ram and want to use Vulkan. Personally, I prefer to run Max Settings on 11.41 with lower FPS. Looks a lot better.
"But I run Vulkan with maximum objects and I dont have this problem!!!"
You may not experience the blurry textures if you:
A)have 11gb of VRAM (might still occur, I can’t test)
B)Aren’t flying over Crowded areas
C)you are using a light aircraft in regards to textures. Laminar C172 etc.
D)Aren’t running in 4k.
Easy way to test is try to fly the Zibo 737 4k Texture version on Vulkan out of LAX w/ maximum objects. It crashes every time for me becuase it says I dont have enough VRAM. Load it up in 11.41 openGL, and its buttery smooth.