isn't amd better at vulkan ?
Remains to be seen; however they did suck at OpenGL performance much like they sucked at D3D11 performance when compared to NV.
Single gpu results are shocking tho. A 7970 outperforms a 980! I wonder if async compute has anything to do with this(FTR im just speculating here)
Unlikely, although if this time iD used the native API compute instead of using CUDA on NV and nothing on AMD it might help matters (see: Rage release).
Most likely, as I said above, this is a case of compared to their OpenGL drivers the Vulkan drivers don't suck as much.
Remember the days when Nvidia just destroyed AMD when it came to OpenGL and now the tables have turned.
But a PC game that is locked at 60FPS and 60Hz with no MultiGPU support when Vulkan is designed with MultiGPU in mind? No thanks, will wait for the actual PC version to be released when the BFG edition comes out in a year.
NV have always been driver performance kings; they throw resources at it. D3D12 and Vulkan have less performance wiggle room and rely more on what the apps are doing - so when you remove the driver overhead, much like with the D3D12 benchmarks floating about before now, you see a better version of how the games are driving the GPUs.
(as to how optimal the games are; well the IHVs can still advise of course..)
As to the second point; no. Vulkan was not designed the mGPU specifically in mind.
Vulkan serves the same purpose as D3D12; to take an old API, with a less than optimal design and produce something which closer matches the hardware, removes overhead on the GPU side and allows for more control, which does, like with D3D12, bring with it mGPU support.
(Just, ya know, more so because while D3D11 had a degree of suck about it, due to the years of piling on crap from a driver writer's pov OpenGL succccccccccccccccccccccked!)