Yea there is no way to say (scientifically, not saying you dont know what runs better on your system) that the API caused the difference and quantify it.
Trying to keep 120FPS going with all of the eye-candy off seems counter-intuitive to me personally.
AMD is going to try to get mantle into the OpenGL specification, or implement them as extensions to OpenGL in their driver. Microsoft will spend money on DirectX.
I can tell you what it isn't: spending millions on Mantle development with the intention of encouraging DX/OGL to make it even more irrelevant than it is now.
If their intention was to simply reduce CPU overhead to encourage Microsoft, they're now out of pocket for millions while their competitors benefit for free. You'd have to be an absolute moron to run a business like that.
Who do you think will adopt Mantle if these optimizations come to fruition?
If you think this is definitely going to end mantle, I think you don't appreciate the complexity of the situation. Firstly, opengl isn't relevant, so let's get that out of the way. With DX12, MS will historically force you to buy a whole new OS for the privilege of using a new API. You'll also have to buy a new gpu most likely, whereas mantle can work with existing hardware. DX12 doesn't seem like it would work on maxwell, so you would have to wait for a new nvidia architecture to be released before you could use it, but kaveri might retroactively support it due to similarities between it and the xbox one.
So you effectively end up with the same sort of dynamic, the low level api that only works on amd cards vs dx11 nvidia cards.
Intel stands to lose the most if bottleneck for gaming moves from the CPU to GPU. It's interesting they would agree here.
With DX12, MS will historically force you to buy a whole new OS for the privilege of using a new API.
I can't believe that after how many years, people still repeat this fallacy.. 😵
[snip]
Could they have back ported it? Possibly, but it wouldn't have been worth the effort..

I can't believe that after how many years, people still repeat this fallacy.. 😵
The reason why APIs sometimes require an OS upgrade, isn't because Microsoft is just trying to squeeze more money out of consumers..
It's because the new API comes with a driver model update as well. Vista had a completely new driver model that added a number of new features and enhancements that increased the stability, performance and capability of the display drivers over that of the XP version..
Could they have back ported it? Possibly, but it wouldn't have been worth the effort..
Same thing with Windows 7 and Windows 8/8.1. Windows 8 came with a new driver model
The same reason anyone will use a Nvidia specific extension? It offers something that they want.Why would anybody use those AMD specific extensions?
OpenGL isn't a threat to mantle since AMD are going to and already have been developing performance orientated OpenGL extensions with the end goal of them being incorporated into the core specification. AMD has had at least one such extension incorporated into the OpenGL specification. I linked to it earlier in this thread.The biggest threat to Mantle is OpenGL. With a software and hardware independent API you can port your game nearly to every plattform on the market.
I can't believe that after how many years, people still repeat this fallacy.. 😵
The reason why APIs sometimes require an OS upgrade, isn't because Microsoft is just trying to squeeze more money out of consumers..
It's because the new API comes with a driver model update as well. Vista had a completely new driver model that added a number of new features and enhancements that increased the stability, performance and capability of the display drivers over that of the XP version..
Could they have back ported it? Possibly, but it wouldn't have been worth the effort..
Same thing with Windows 7 and Windows 8/8.1. Windows 8 came with a new driver model
Until someone can directly answer how something with less far less than 1/3rd market penetration (not all AMD cards support mantle) is going to "take out" D3D, which has 100% market penetration and is used as the API in Xbone, then this conversation is useless.
You mean financially wouldn't have been worth the effort?
Both financially, and practically. Changing driver models, especially to the degree that was done between XP and Vista, is not trivial I'm sure, and would have required a major rewrite of the OS's code.
In instances like that, I think it's better to start from scratch and do it properly for the greatest impact. Microsoft has shown that it's willing to break compatibility between DirectX versions to move the technology forward, and DirectX sometimes requires a new driver model to add or expose new features.
DX9 to DX10 was such a paradigm shift..