As I saw 3Dmark being on sale for cheap, I grabbed that and got some results: Interesting bit is that CPU is still limit with Vulkan too. SC Cinebench R15 is 174 points, 40Mbeams/s for single car, so not the slowest there. For 60fps I got these numbers ~38 000dc DX11 ST ~61 000dc DX11 MT ~390 000dc Vulkan Those are of course just drawcalls, not much running on CPU, any other stuff running on same CPU thread will reduce that quite a bit. Still 3800dc would be like 10% of single CPU thread load and that is which after there is potential to drop below 60fps in BeamNG, so there must be something associated to drawcalls or something that increases among them linearly *or close to) to cause such low limit. But what is amazing is that Vulkan can do over 10 times more drawcalls and 6700 has only 8 threads, so it is not only because it uses more threading, but even within single thread it is more efficient.
Vulkan has shown its worth in some games already too (like Doom's 2016 reboot). The best part of Vulkan though is that it is like DX12, but is not limited to Windows 10. AMD Radeon video cards also tend to do well with it since AMD originally developed it under the name of Mantle API.
Well, Vulkan replaces Mantle and was based partly on it. They both also served the same purpose. I like to think of Vulkan as the successor to Mantle.