Downside of Mantle

[Xorbot]

I've arrived at a chilling forecast during my analysis and thought about Mantle.  Since this is AMD's proprietary technology, it is not likely that there is a simple way to support the unique features of nVidia's architecture.

 

Let's establish a few things.  OpenGL is an API which exposes the hardware-specific features, if they are implemented.  I'll give some very basic examples of these extensions purely for discussion/illustration purposes:

• GL_ATI_shader_texture_lod
• GL_NV_fragment_program2

These extensions works as follows.  During the initialization of an OpenGL program, the programmer is able to query the driver through OpenGL function calls to see if the extensions exist.  If so, then the engine can do further initialization that are related to the extensions in question.  For example, if an nVidia-specific extension exists, it can result in faster render times due to a feature being supported by the hardware.  In this case, however, the extension would not be available on AMD's hardware, and thus not available as an OpenGL extension when running the game on AMD video cards.  Usually there is an equivalent extension, and the engine would handle these features properly and adequately (providing the game engine isn't crappy or devoid of advanced features).

 

So, with my admittedly light knowledge of Mantle, it is an API (Application Programming Interface) with direct functions to these extensions.  Since Mantle works for GCN and onward, it is assumed that the OpenGL-equivalent extensions exists as though they are a part of the standard API.  For example, there is no need to query if "GL_ATI_shader_texture_lod" exist, and then use it with the chance of it being buggy via the current AMD OpenGL driver.  Instead, Mantle would expose such a feature as though it were a "fact" or a part of normal API.  It would be as common to use as the "glVertex3f" function, which *MUST* be supported on *ALL* OpenGL driver implementations and hardware.

 

So, now onto the next part.  I could foresee nVidia responding with their own Mantle.  Of course, it wouldn't be called Mantle, but rather another branding.  The same thing would exist, whereby there are standard API function calls are designed for nVidia specific hardware, and likely would support Kepler and onward.  I know that one great feature that is getting a lot of attention lately is nVidia's H.264 processing abilities via Kepler chips.  With this feature being a "fact" of Kepler-based devices, there would be standard API function calls for H.264 encoding.

 

An example would be to call a function to begin encoding the last X frames rendered into an in-memory H.264 video stream, whereby it can be played back through a surface texture.  This would lead to a really interesting indie title whereby the past actions are recorded and played-back within the game via television screen meshes.  This example is to show that there are also nVidia-specific features that would exist through a Mantle-like API, and thus would be a game that could only be supported (via hardware) on nVidia cards.

 

That's where the downside lies.  That is main issue of the downside of Mantle.  In order to support that awesome nVidia H.264 feature on AMD renderers/Mantle, a software-based work-around must be created.  Either that, or the game must be released for nVidia-only hardware, which is not a likely scenario for developers and publishers who wish to turn a profit.

 

As a result, I foresee *ANOTHER* API coming.  If we presume that an nVidia Mantle-like API exists, as well as AMD's Mantle, we could see *ANOTHER* API that sits on top of both.  Let's call it "Crust", since we are going with a naming scheme that relates to the layers of planet Earth.  The Crust API is basically another set of functions that will either execute a hardware-supported version of a feature, or a software workaround.  In the H.264 example, the Crust API function would redirect to nVidia's H.264 features, but for AMD, it would be redirected to a software-based solution.

 

Does this sound familiar?  It is basically DirectX again.  Albeit, that is a very simplified analogy, and writing about the minute differences would result in a 10-page post.  So, in simple terms, this whole Mantle and nVidia API thing may result in a situation where games are back to the so-called "bloated" (Linus and Slick's term) DirectX.  Sure, things may be improved in very specific situations.  Also, console ports may be improved slightly.  However with my experience as a game programmer for many years, I feel that in the end we are not going to be better off, at least in large measurable terms.  If anything, the performance gains may save us a generation of video cards.  What I mean by this is that the 7970 can act as a 9970 (or whatever that new R9 XYZ equivalent name is) through the optimizations.

 

Once gamers and developers "get used to" Mantle as a norm, then there is no tangible difference.  We'll still be stuck in the same boat as we were with DirectX in a few generations from now.  Developers will have new headaches in the future, and that is to "fight" with the Crust, Mantle, and nVidia API's.

 

[Liam-McShane]

I don't see this happening. Mantle is a huge improvement over DirectX and if enough devs get behind it, Nvidia may be forced to approach AMD about it. I don't see Nvidia coming out with their own version for a few years, during this time mantle may have already gained enough momentum for Nvidia to not bother making their own.

[Xorbot]

I don't see this happening. Mantle is a huge improvement over DirectX and if enough devs get behind it, Nvidia may be forced to approach AMD about it. I don't see Nvidia coming out with their own version for a few years, during this time mantle may have already gained enough momentum for Nvidia to not bother making their own.

 

You may be right as long as Mantle is truly a huge improvement over DirectX.  However, I cannot claim you are right until I actually see Mantle in action.  I write this post because I am reminded of a time when MMX of Pentiums where supposed to change everything and blow the world away of gaming.  I will grant that Mantle is probably a more significant of a step than MMX, but we've already seen in the past how a new technology was supposed to blow everyone away but actually didn't.

[Cyberpunk177]

[Liam-McShane]

You may be right as long as Mantle is truly a huge improvement over DirectX.  However, I cannot claim you are right until I actually see Mantle in action. 

Very true, it's all guessing until we see how it performs and whether developers decide to use it 

 

Edit: Just read this https://linustechtips.com/main/topic/61138-call-of-duty-will-also-support-amds-mantle/

 

That's now two big developers and titles using it, they must see something in it. Fingers crossed

[Guest]

this guy is wrong in every way imaginable

i didnt even need to read what he wrote.

 

 

he is wrong

[Xorbot]

Very true, it's all guessing until we see how it performs and whether developers decide to use it 

 

Edit: Just read this https://linustechtips.com/main/topic/61138-call-of-duty-will-also-support-amds-mantle/

 

That's now two big developers and titles using it, they must see something in it. Fingers crossed

 

If Mantle works out, my next rig can very well be a pure AMD system -- AMD processor and AMD video card(s).

[carolkarine]

nvidia can't come out with their own, they don't have the backing of the developers. (when I say this, I mean AMD has both the PS4 and xbox one on GCN) it will become incredibly easy to port to AMD. AMD will perform better. hands down, GG nvidia unless they can do something nuts.

[silencerbob]

nvidia can't come out with their own, they don't have the backing of the developers. (when I say this, I mean AMD has both the PS4 and xbox one on GCN) it will become incredibly easy to port to AMD. AMD will perform better. hands down, GG nvidia unless they can do something nuts.

Xbox one uses direct x... Sorry. I don't want to make this another amd fanboy vs nvidia fanboy thread.

[TooManyErrors]

Nvidia has already had an API, even though its not as powerful as of now. Its very cleverly called NVAPI.

[carolkarine]

Xbox one uses direct x... Sorry. I don't want to make this another amd fanboy vs nvidia fanboy thread.

 

xbox one will use a version of mantle cause it's a better API. developers may have a directx option, but why would they bother when AMD hands them something that performs better?

[Guest]

this guy is wrong in every way imaginable

i didnt even need to read what he wrote.

he is wrong

Instead of merely stating he is wrong, explain why.

[DeViLzzz]

A downside to Mantle ?  Man I can't remember a flaw in Mickey Mantle's game.  

[NinjaStyle013]

It would be so sweet for amd and nvidia to co operate on an API to benefit every gamer then leave it to the hardware to battle it out.

[KaareKanin]

xbox one will use a version of mantle cause it's a better API. developers may have a directx option, but why would they bother when AMD hands them something that performs better?

Is his confirmed fact or just speculation and internet hype? I only ask because unless there's support for mantle in the OS of a device, I don see it working. And I don't see anyone but MS controlling drivers for the xbone...

[Guest]

Is his confirmed fact or just speculation and internet hype? I only ask because unless there's support for mantle in the OS of a device, I don see it working. And I don't see anyone but MS controlling drivers for the xbone...

im sure they will give limited support because then that means their dx kinda dies

or 

they give full support because it improves user experience and gameplay(most unlikely)

[qwertywarrior]

I'm hoping Mantle takes off so we can all move to Linux, I would have moved to linux a long time ago if it was a viable gaming platform.

I'm hoping OpenGL takes off so we can all move to Linux, I would have moved to linux a long time ago if it was a viable gaming platform.

[qwertywarrior]

I'm fine with either taking off. OpenGL means I can use my 780 I ordered and Mantle means I'll get a 290x and move to linux So either is fine

i think both will take off

but like every one says

keeping things open is the way to go

no body likes things locked down  just look what DX did

[KaareKanin]

im sure they will give limited support because then that means their dx kinda dies

or 

they give full support because it improves user experience and gameplay(most unlikely)

But if DX dies, only the Win-PC platform suffers, and MS doesn't seem to care about that. And I don't think mantle will improve consoles, because consoles are usually low-level optimised anyway, mantle will only help bringing low level to the PC and bridge the transition for developers.

[themodernagenb]

Couldn't MS just make DirectX better? You would think Mantle would push them to do so.

[Brian A Cerda]

Developers will decide if games are coded in mantle, and so far it seems not only did they request mantle, the seem to be using it already. Frostbite 3 using mantle and next gen consoles using AMD graphics will give mantle all the room to fly it needs. If developers can make more money using mantle, the simply will use it. and if they can't it will vanish over time.

[orangecat]

Keep in mind mantle is open source so maybe nvidia can make their own version of it based off AMDs version and the only difference is that AMD specific hardware instructions will use nvidia ones instead. hopefully there is no compatibility issues and i really hope nvidia doesnt make their own api because lets get serious for a minute. If nvidia and amd have their own apis things will get messy why do i need direct x, opengl, mantle and whatever nvidia releases also if things turn out like you say then there will be no compatibility so developers will have to code the game for both making it more work for them and will make the game have more visual bugs.

[nicehat]

There will be support for both APIs. There is no way in heck that game devs are going to completely alienate nVidia. Games will be optimized to run on Mantle, but will suffer smaller possibly inconsequent performance hits on NVAPI especially with updates etc. This is currently the case in point with what BF4 will be. 

[OddlyShapedTree]

Very interesting and honestly plausible. The only thing that would prevent this IMO would be maybe you are able to buy a Nvidia or AMD optimised version of a game? I don't know if that would work but it would be cool. But If worse comes to worse then we would just have a better version of DirectX sucks but probably would be better than what we have now.