Ah, one should be careful with such a blanket statement (unless you have some more detailled information?). Benchmarks are rarely unbiased and never fair, and interpreting the results can be tricky. I'm not trying to defend nVidia here, and you might quite possibly even be right, but I think solely on the linked results, this is a bit of a hasty conclusion.
Async compute is looking to be a killer feature for DX12 / Vulkan titles. The benchmarks indicate that Pascal's implementation of async compute isn't half as good as AMD's.
From what one can see in that video, one possible interpretation is "Yay, AMD is so awesome, nVidia sucks". However, another possible interpretation might be "AMD sucks less with Vulkan than with OpenGL". Or worded differently, AMD's OpenGL implementation is poor, with Vulkan they're up-to-par.
Consider the numbers. The R9 Fury is meant to attack the GTX980 (which by the way is Maxwell, not Pascal). With Vulkan, it has more or less the same FPS, give or take one frame. It's still way slower than the Pascal GPUs, but comparing against these wouldn't be fair since they're much bigger beasts, so let's skip that. With OpenGL, it is however some 30+ percent slower than the competing Maxwell card.
All tested GPUs gain from using Vulkan, but for the nVidia ones it's in the 6-8% range while for the AMDs it's in the 30-40% range. I think there are really two ways of interpreting that result.
Not really, because all games that have async compute AMD gains much more than pascal, including direct X titles. Check this out if you don't believe me:
That benchmark shows that samoth is correct. Async Compute seems to be improving performance by 2-5% for AMD, which is far from the massive improvement in Doom. The "AMD is awful at OpenGL" theory seems even more likely now.