Yep exactly the same with DirectX 12, it’s a lower level API than DirectX 11 therefore allowing more efficient calls but is a little more challenging to code.
When Laminar Research implemented Vulkcan they had all sorts of issues with texture memory utilisation for example which was to some degree managed in OpenGL by the library so the sim would crash often until they wrote routines to manually manage the texture memory allocation which they never needed before.
From the analysis I’ve seen Vulkan offers every so slightly higher average frames over DirectX 12 but DirectX 12 offers higher minimum 1% frame scores so would achieve smoother performance which might be better for sims but it’s much of a muchness. Both platforms now offer ray tracing capabilities.
For me utilisation of ray tracing is the big advantage although if they coded DirectX 12 efficently we should get performance improvements too.
The likely improvements I would expect should be:
- More fps and smoother flights - less stuttering.
- Ray traced reflections (would probably be limited to cockpit / water scenes) - removes the grainy reflections currently seen in DirectX 11.
- Ray traced shadows (would probably be limited to players plane/cockpit) - shadows would be vastly smoother and have no flickering.
- More accurate plane and cockpit lighting reflecting external conditions.
Ultimately these improvements make for a better performance and visual experience in VR so if you have a VR headset you definately want these changes in the sim.