The AMD Mantle Thread

[24601]

http://www.hardwarecentral.com/showthread.php?24783-DirectX-vs-Glide

http://www.hardwarecentral.com/showthread.php?24783-DirectX-vs-Glide&p=152737#post152737

All about the draw calls.

Diablo II is a classic case of massive CPU overhead + massive CPU use (because of how the game worked) leading to them resorting to Glide in the middle of development for performance.

DirectX 8 had a pretty heavy overhead for draw calls (compared to the versions after)

The DirectX 8 build actually originally had the same quality as the Glide path, but they lowered the quality for better performance, since Glide guaranteed use of 3dfx hardware, while DirectX was expected to run on everything, including absolute trash hardware (Like the S3 Virge 3D Decelerator I had :awe.

 

[Dribble]

The point of Mantle is to take console optimizations and port them straight into PC's. That work has been getting done for the entire existence of consoles. If it plays out like they are saying it will not mean much additional work for the PC version. So, dev codes mantle version for ps4 and xbone, and it work son GCN cpu's on PC. Dev codes for DX11 port like always. It should be the same amount of work, or very little extra work compared to what they have always done.

But the consoles will be fully optimised without mantle - MS and Sony will both provide very efficient interfaces to the consoles just like they have done for all the previous versions. Right now they have much bigger dev teams then AMD can hope to muster doing just that. MS and Sony will not let AMD control the low level API to their consoles.

So that leaves Mantle as another low level API just for GCN on PC's, which due to market share basically will be ignored by devs unless AMD pump $million dollars into the game they are making. This is very similar to nvidia and physx/3d vision.

Hence right now Mantle is just a very impressive bit of power point marketing. You pay one company to put extra optimisations for your cards on the PC in one game, and then play on the discussion about what having all AMD powered consoles means and make some grand claims with a distant expiry date.

That gets all the fanboys hyped up and gets everyone questioning their purchases for the next year. After a year people will realise it mostly came to nothing but by then AMD will have made the extra sales so job's done.

 

[Grooveriding]

Why are game developers already discussing how they will be using on Mantle then ? And why on earth wouldn't MS & Sony use AMD's low-level API for their consoles that contain hardware made by AMD ?

 

[omeds]

Sony and MS are using customised code for their customised hardware.

 

[smackababy]

It isn't just about them using the low level API. Mantle can be exactly the same on consoles and PCs, but that doesn't change the problem with Mantle.

Currently, with DX you have something like this: call dxFuction() > function does some image processing > function utilizes drivers > accesses GPU > draws image on screen.

Mantle, from what I've seen in the slides, doesn't have the "does some image processing" part. So, the Mantle stack is [developer writes a function to do processing] > calls Mantle > accesses GPU > draws image on screen.

Now, consoles have [Xbox or Sony high level API].processingFunction() > Mantle stack.

Mantle can't just be included in engines, unless the engine developers offer a high level API similar to DX (minus the no direct GPU access) OR the developers write their own. The problem is most, if not all but a handful, of developers could not write their own DX like functions.

That isn't even considering all the other stuff DX does (like DirectSound and DirectInput).

 

[Stuka87]

But the consoles will be fully optimised without mantle - MS and Sony will both provide very efficient interfaces to the consoles just like they have done for all the previous versions. Right now they have much bigger dev teams then AMD can hope to muster doing just that. MS and Sony will not let AMD control the low level API to their consoles.

So that leaves Mantle as another low level API just for GCN on PC's, which due to market share basically will be ignored by devs unless AMD pump $million dollars into the game they are making. This is very similar to nvidia and physx/3d vision.

Hence right now Mantle is just a very impressive bit of power point marketing. You pay one company to put extra optimisations for your cards on the PC in one game, and then play on the discussion about what having all AMD powered consoles means and make some grand claims with a distant expiry date.

That gets all the fanboys hyped up and gets everyone questioning their purchases for the next year. After a year people will realise it mostly came to nothing but by then AMD will have made the extra sales so job's done.

I think you misunderstand what Mantle is.

Mantle is not on consoles, nor will it ever be most likely. The point of Mantle is to take code that was written for consoles, and allow it to run on a PC. You take a call on a console that makes a call straight to the GPU (Which AAA games do, indy games will be using higher level API's). Now on a PC you take this call, and it is now routed through Mantle. Mantle then makes the call to the GPU.

It does not work the other way around. There is no need for Mantle to be on consoles, it is not required to be. AMD is not trying to control any API on the consoles, so Sony and MS have nothing to worry about in regards to that.

 

[Paul98]

I think you misunderstand what Mantle is.

Mantle is not on consoles, nor will it ever be most likely. The point of Mantle is to take code that was written for consoles, and allow it to run on a PC. You take a call on a console that makes a call straight to the GPU (Which AAA games do, indy games will be using higher level API's). Now on a PC you take this call, and it is now routed through Mantle. Mantle then makes the call to the GPU.

It does not work the other way around. There is no need for Mantle to be on consoles, it is not required to be. AMD is not trying to control any API on the consoles, so Sony and MS have nothing to worry about in regards to that.

Yeah, I sort of see it like this they already have an API that is being used on the consoles. They are using the same GPU as their current PC GPU line. They can make something that works on PC so that what is already written on console can work on the PC. This also addresses some complaints and problems that are in the PC graphics programming world.

Is there any word on a date when people can start downloading the API?

 

[smackababy]

Yeah, I sort of see it like this they already have an API that is being used on the consoles. They are using the same GPU as their current PC GPU line. They can make something that works on PC so that what is already written on console can work on the PC. This also addresses some complaints and problems that are in the PC graphics programming world.

Is there any word on a date when people can start downloading the API?

It isn't going to be a write once / run anywhere solution. The API calls you make on console will differ from the API calls you make on PC (the exception might be the Xbox One / DX, but I am not sure exactly how similar those APIs are, as I've never developed for the Xbox One).

Mantle, if it is only a low level API, will run entirely separate of any DX code path. The DX pipeline will have to be emulated in some fashion before the Mantle driver calls are made. Otherwise, you're basically just drawing static imaged on screen, which is no real help for gaming.

At least, that is what I've gotten from the limited information we have about Mantle. Once the API is finished, we should get a lot more information on what exactly it does and if it can be used in conjunction with DX (which would be best case scenario; make DX calls where you want and have the ability to make Mantle calls to bypass the DX pipeline in areas you want more efficiency).

 

[zlatan]

So considering that the GPU is entirely unrelated to any API. How can GPU performance increase with Mantle?

Game->DirectX API, AMD Driver->GCN
Game->Mantle API, AMD Driver->GCN

Game, API and Driver is CPU only.

This is not that easy.
Here is the DX pipeline:
game->DirectX->UM driver->command buffer with software queue->KM driver with DMA buffer->hardware queue->hardware

The Mantle will be a console style API so it should use this kind of pipeline:
game->Mantle->thin driver->command buffer->hardware queue->hardware

 

[Stuka87]

It isn't going to be a write once / run anywhere solution. The API calls you make on console will differ from the API calls you make on PC (the exception might be the Xbox One / DX, but I am not sure exactly how similar those APIs are, as I've never developed for the Xbox One).

Mantle, if it is only a low level API, will run entirely separate of any DX code path. The DX pipeline will have to be emulated in some fashion before the Mantle driver calls are made. Otherwise, you're basically just drawing static imaged on screen, which is no real help for gaming.

At least, that is what I've gotten from the limited information we have about Mantle. Once the API is finished, we should get a lot more information on what exactly it does and if it can be used in conjunction with DX (which would be best case scenario; make DX calls where you want and have the ability to make Mantle calls to bypass the DX pipeline in areas you want more efficiency).

Why would you need to emulate the DX code path? Not only would that defeat the purpose of Mantle, it would be slower.

DirectX is not used in any shape or form for graphics when Mantle is used. The whole point of it is to bypass all the overhead of DirectX. The point of it is to run console code without porting the engine to DirectX. It isn't entirely a code once, run on Mantle/Console, but it will be very close.

 

[BoFox]

DX is the reason we all use windows and not free OSes like Linux, because "bloatware" allows everyone to play, not just a select few that buy the product that an unreleased game ends up using.

I've never seen anyone say DX11 graphics overhead was a problem, it has always been about draw calls, even AMDs own slides mention nothing about increased graphical performance, only "enhancements" - though they quite clearly spelled out the reduction in draw call overhead...

Bitcoins do better on AMD because they can do an op a cycle whereas Nvidia cards required three.

A poorly written game on any API is still a poorly written game, just as a bad example is bad no matter what the comparison being made is.


At this point it's just words and opinions, if there were any facts there would be no debate.

Hopefully BF4 ends this debate, and I'll be in a decent spot to watch it all unfold since I can max my usage at 1125/1500 in CF for around 60 FPS without being cpu limited.

Let's say that there's a game called "Bitcoin". DirectX makes it so that it requires 4 or more cycles on all GPUs, because of its bloated API that ensures compatibility with Nvidia and AMD, and ESPECIALLY Intel's crap DX11 IGP. AMD knew that "Bitcoin" can on just 1 cycle, like as if it were massively hyperthreaded, but they have not yet done anything about developing their own API, other than optimizing their DirectX drivers, and nothing more. Imagine if DirectX didn't allow programs to take advantage of Intel's Hyperthreading (which easily gives 40% more performance on "99%" usage with 2x the virtual cores than "99%" usage with the physical cores).

Hence, AMD is finally making a move on the PC front. They have far more traction thanks to PS4 and XBOne developers being 100% familiar with GCN uarch, the basic requirement of Mantle API that AMD wants to introduce to the PC. Mantle will definitely share many and a many lines of code with PS4 and XBOne games that were coded-to-the-metal for these platforms, so it won't be too difficult for devs to optimize PC ports using these lines of code as well. With AMD working on Mantle drivers, AMD, with best knowledge of their own uarch, helps devs to further optimize, squeezing every last bit of what their GCN-based GPUs can offer, effectively turning them into ideally efficient power-viruses.

Say, a Geforce runs this Bitcoin game at 4 cycles per op, and yet still requires 200W to do so. A Radeon could still draw 200W at 4 cycles per op thanks to DirectX, but with Mantle, draw 300W at 1 cycle per op and perform up to 2.5 times as fast (as other bottlenecks start to limit the GPU like bandwidth, ROPs, etc..).

Fun speculation, eh? Hehe..

 

[psoomah]

This looks to be the low level API that unites at least 3 platforms.......along with a 4th around the corner.

The fourth would be Steam? Gabe might not like it but AMD is the future. With Mantle showing up on more and more next gen games he really can't afford to ignore, or not support, it.

I would add a fifth - ARMv8 + 20nm + Mantle = AAA 'hardcore' gaming capability. ALL the major ARM players are HSA foundation founders. I suspect the AMD Developer Conference will unveil ARM Mantle partnerships + and an AMD ARMv8 + GCN retail chip coming in 1H 2014. This will enable ARM based gaming tablets with joysticks and triggers playing BF4 (and other games) in it's full glory. An Xbox gaming tablet would also become viable.

A possible sixth is Apple - a relatively easy and inexpensive way to get into AAA gaming.

In a couple years EA can do their primary coding on the PC and do easy ports across ALL the ecosystems. As could the rest of the developers.

AMD said it has several more Mantle partners. In two or three years when 25% or more PC games are Mantle optimised, and that number growing steadily, who's going to buy an Nvidia GPU?

I'm thinking the AMD Developers Conference 2013 will be a very very bad three days for Nvidia.

 

[psoomah]

It increasingly appears all the major engines will be supporting Mantle including Unity.

The bottom line is clear enough ... when 25% of next gen games are Mantle optimized, and with that percentage steadily growing, who will buy an Nvidia AIB GPU? Or an Nvidia based 'gaming' laptop?

 

[PPB]

The bottom line is clear enough ... when 25% of next gen games are Mantle optimized, and with that percentage steadily growing, who will buy an Nvidia AIB GPU? Or an Nvidia based 'gaming' laptop?

The very same people that keeps buying 770s at 400 bucks when you can see 7970GE as low as $280.

 

[ICDP]

The very same people that keeps buying 770s at 400 bucks when you can see 7970GE as low as $280.

There is no boubt some people make what are considered insane decisions.

 

[PPB]

The problem is when those people cant recognize the underlying reason they are going for the less valuable proposition.


I have a friend who just bought a Zotac 780 recently, he knows I'm very picky on GPU value (still I'm nothing compared to the likes of RussianSensation, lol). When I asked why he went that route, he just responded "because he liked it". That in my book is a lot more respectable than people that start to rationalize why they went with the worse value.

 

[cmdrdredd]

It increasingly appears all the major engines will be supporting Mantle including Unity.

The bottom line is clear enough ... when 25% of next gen games are Mantle optimized, and with that percentage steadily growing, who will buy an Nvidia AIB GPU? Or an Nvidia based 'gaming' laptop?

It doesn't appear that at all. There is only one engine using it by I e developer and one publisher.

 

[caswow]

It doesn't appear that at all. There is only one engine using it by I e developer and one publisher.

developer summit in november amd said they will reveal more about mantle and reveal more developer who are working with mantle

 

[Dribble]

I think you misunderstand what Mantle is.

Mantle is not on consoles, nor will it ever be most likely. The point of Mantle is to take code that was written for consoles, and allow it to run on a PC. You take a call on a console that makes a call straight to the GPU (Which AAA games do, indy games will be using higher level API's). Now on a PC you take this call, and it is now routed through Mantle. Mantle then makes the call to the GPU.

It does not work the other way around. There is no need for Mantle to be on consoles, it is not required to be. AMD is not trying to control any API on the consoles, so Sony and MS have nothing to worry about in regards to that.

Yes, so it's an alternate rendering path to DX in some instances. You can't just copy paste from consoles to the PC, even if it is similar. You'll have to develop it, test it, support it, etc. This takes time and money. Think - console devs can't even be bothered to properly switch the ui over to support the PC, why would they consider all the effort of a separate rendering path for 9% of their potential customers (which I think is the GCN % from steam).

Will all that effort and cost adding it effect sales of their game? No - they'll still sell the same number of copies as people who were going to buy it will buy it whether or not it's slightly faster on their PC. The only sales it effects are AMD's which is why AMD will be the one paying for it's addition.

 

[smackababy]

Yes, so it's an alternate rendering path to DX in some instances. You can't just copy paste from consoles to the PC, even if it is similar. You'll have to develop it, test it, support it, etc. This takes time and money. Think - console devs can't even be bothered to properly switch the ui over to support the PC, why would they consider all the effort of a separate rendering path for 9% of their potential customers (which I think is the GCN % from steam).

Will all that effort and cost adding it effect sales of their game? No - they'll still sell the same number of copies as people who were going to buy it will buy it whether or not it's slightly faster on their PC. The only sales it effects are AMD's which is why AMD will be the one paying for it's addition.

I think what Mantle could possibly do is force MS' hand to make DX's pipeline more open and customization. Even if DX had the ability to make low level calls while skipping the pipeline, so of like a dxAPI.directCall(ImageObjectYouWantToRender) function and it handled the driver level stuff (NV or AMD and their optimizations), I think a lot of developers who complain about DX would be happy. So, if Mantle really gives some stellar performance, perhaps MS will not want to lose DX being the standard and let developers have more freedom; all while keeping the current DX stuff intact, so lesser developers can still have the ease of use of it's current form.

 

[redhotiron2004]

I think what Mantle could possibly do is force MS' hand to make DX's pipeline more open and customization. Even if DX had the ability to make low level calls while skipping the pipeline, so of like a dxAPI.directCall(ImageObjectYouWantToRender) function and it handled the driver level stuff (NV or AMD and their optimizations), I think a lot of developers who complain about DX would be happy. So, if Mantle really gives some stellar performance, perhaps MS will not want to lose DX being the standard and let developers have more freedom; all while keeping the current DX stuff intact, so lesser developers can still have the ease of use of it's current form.

This....
Well said!

 

[Grooveriding]

Really looking forward to seeing these Mantle Battlefield 4 benches.

https://twitter.com/repi/statuses/387582507710828546

Johan Andersson ‏@repi So expect some improvements in the next #BF4 OpenBeta patch. Though Win8 w/ our DX11.1 backend is definitely the fastest path (until Mantle)

 

[Crap Daddy]

Cool. The game runs better on an OS used by a small minority of gamers. Mantle will bring improvements for another, albeit larger minority. Dice seems to be more interested in promoting software and hardware than selling games.

 

[Kenmitch]

Cool. The game runs better on an OS used by a small minority of gamers. Mantle will bring improvements for another, albeit larger minority. Dice seems to be more interested in promoting software and hardware than selling games.

http://www.winmatrix.com/forums/ind...111-platform-update-for-windows-7-kb-2670838/

I didn't try it to see if 11.1 is trully available. Guess gpu wojld need to support it also.

 

[Deasnutz]

Cool. The game runs better on an OS used by a small minority of gamers. Mantle will bring improvements for another, albeit larger minority. Dice seems to be more interested in promoting software and hardware than selling games.

Yes, Dice please cripple the game so it runs [poorly] on both the best and most capable systems, so the cheap gamers don't feel bitter.

Warning issued for profanity.
-- stahlhart