DirectX 12

[Carfax83]

That's unfortunate, I was hoping for more of a clean sheet approach.

Why is it unfortunate? DX11 multithreading did work, but it was flawed because it wasn't thread safe and driver threads could collide with game threads if things weren't properly managed..

DX12 removes that limitation, and makes the overall process much more efficient. This was probably the only way they could implement an advanced multithreading technique, that works across ALL architectures because it relies primarily on the GPU driver, and not the API for thread management.

If I remember correctly, Mantle is completely different and has no driver thread(s) at all..

 

[f1sherman]

They are talking up DX12 now, an API two years away with a few obtuse powerpoint slides...

How do you figure DX12 MIA, when DX12 games will already be released at that time?

Figure of speech, slight exaggeration or something else?

 

[Gloomy]

Why is it unfortunate? DX11 multithreading did work, but it was flawed because it wasn't thread safe and driver threads could collide with game threads if things weren't properly managed..

DX12 removes that limitation, and makes the overall process much more efficient. This was probably the only way they could implement an advanced multithreading technique, that works across ALL architectures because it relies primarily on the GPU driver, and not the API for thread management.

If I remember correctly, Mantle is completely different and has no driver thread(s) at all..

So wait, let's clarify for a second. So you think DX11MT has problems after all? What about all those threads you made praising it and Nvidia for supporting it? Did DX12 make you see the light? Why didn't Mantle?

 

[Carfax83]

So wait, let's clarify for a second. So you think DX11MT has problems after all? What about all those threads you made praising it and Nvidia for supporting it? Did DX12 make you see the light? Why didn't Mantle?

Quote me where I said that DX11 MT had no problems and was absolutely perfect.

I supported DX11 MT, because there was evidence that it was effective (on NVidia hardware at least), but I was never blind to the limitations. Those limitations have apparently been addressed with DX12, and then some however..

Mantle was completely different, as it was architecture dependent. That alone is a good reason to be against Mantle.

 

[Carfax83]

How do you figure DX12 MIA, when DX12 games will already be released at that time?

Figure of speech, slight exaggeration or something else?

I think it's likely we'll see DX12 titles before late 2015, though not native ones. DX12 seems to have quite a lot in common with DX11, so I'm sure some developers will release DX12 updates for DX11 titles to take advantage of the performance increases, just like we saw previously with DX11 being tacked on to DX9 games for extra eye candy.

 

[OCGuy]

D3D is in Xbox, every DX11 GPU will support at least most of 12.0 That is 100% of the installed discreet base, + Xbone.

 

[Phynaz]

Interesting, it appears that DX12's multithreading is a highly improved and more efficient version of the DX11 multithreading technique which uses command lists to record and upload data to the GPU:

Source

What does this mean? It means that NVidia's drivers will already be optimized for DX12 to a great extent, as NVidia has been fine tuning it's drivers for DX11 multithreading for years..

That was one of my concerns with DX12. NVidia spent all of that time and resources refactoring their driver codebase for DX11 multithreading, but if DX12 was similar to Mantle, then all of that effort would have been for naught. But now we know that DX12 uses a similar, but vastly improved multithreading technique as DX11..

AMD on the other hand, has never bothered to implement DX11 multithreading, so they will have a lot of work to do catching up to NVidia...

So all of those people like Charlie that are saying DX12 is a rip off or copy of Mantle are incorrect. DX12 appears to be a more evolved and refined version of DX11.

You missed the part in your own quote where they said the driver model is new. I don't see how you can make the leap that somehow Nvidias drivers are already optimized for an API that is two years away.

If anything, with having Xbox running DX12, that would but AMD in better shape driver wise. You can bet Microsoft will throw their weight behind AMD's drivers in their battle with Sony.

 

[AnandThenMan]

Quote me where I said that DX11 MT had no problems and was absolutely perfect.

You praised Nvidia repeatedly for their MT drivers, went so far as to call the improvements "massive" and called AMD a major failure for apparently not having same. You also basically said that MT was a big reason Nvidia didn't need a Mantle like API.

You also said that Nvidia would benefit very little if they adopted Mantle, yet DX12 is very much in the mold of Mantle. It's all there in your post history.

I think it's likely we'll see DX12 titles before late 2015, though not native ones.

Didn't you say Win9 would be here by the end of 2014? I remember thinking that is wildly optimistic. Apologies if it was not you.

 

[norseamd]

D3D is in Xbox, every DX11 GPU will support at least most of 12.0 That is 100% of the installed discreet base, + Xbone.

x box one uses an endemic version instead of the regular dx versions if i remember right. they might be able to patch some of dx 12 into the x box one dx version

EDIT: understood your post more i think. you were talking about x box one dx and pc dx. got it. sorry

 

[Carfax83]

You missed the part in your own quote where they said the driver model is new. I don't see how you can make the leap that somehow Nvidias drivers are already optimized for an API that is two years away.

If you're going to quote me, at least do it properly.

I said NVidia's drivers should already be optimized to a "great extent." That doesn't mean they are fully optimized for DX12.

Of course they will have to do some work, but the fact remains that NVidia's drivers are already highly optimized for DX11 multithreading, and DX12 uses a more advanced and efficient form of the same technique..

And you will note, that the Forza 5 DX12 demo was done on NVidia hardware, with NVidia drivers..

 

[DarkKnightDude]

Sounds like BS to me that they've been working on it for 4 years. Probably not till they realized Xboxone was lacking in the CPU department and Mantle showed up.

 

[f1sherman]

And you will note, that the Forza 5 DX12 demo was done on NVidia hardware, with NVidia drivers..

What would be the idea of MS humiliating their biggest DirectX 12 contributor?

If DX12 had anything to do with Mantle, the least Microsoft could have done is - not feature it on competitor's HW


But apparently Microsoft is having none of it.

Daniel 20 Mar 2014 11:13 AM #

from what I saw AMD is participating in the project and from what I understand the Direct X12 will be a low-level API
so I would like to leave a question, is there any link between Direct X12 and AMD MANTLE?
the mantle served as inspiration or something?


That Guy Who Does Stuff With C++ 20 Mar 2014 11:18 AM #

MANTLE didn't serve as inspiration; the question that spawned MANTLE did, however.

 

[Carfax83]

You praised Nvidia repeatedly for their MT drivers, went so far as to call the improvements "massive" and called AMD a major failure for apparently not having same. You also basically said that MT was a big reason Nvidia didn't need a Mantle like API.

And? Where did I say that DX11 MT was perfect and not in need of refinement. Show me that, and I will eat my socks. We've already been over this countless times. DX11 MT resulted in big gains (similar to Mantle) in the titles that used the technology, and it was already part of the DX11 spec so there was no reason for AMD not to support it.

Tons of people, including AMD users complained about AMD not implementing that feature in their drivers, because it meant that less developers would end up supporting it in their games..

You also said that Nvidia would benefit very little if they adopted Mantle, yet DX12 is very much in the mold of Mantle. It's all there in your post history.

NVidia obviously wouldn't benefit as much as AMD from Mantle, because NVidia's DX drivers are more efficient, and Mantle appears to have strong ties to GCN architecture. And DX12 is nothing like Mantle. The concept may be similar, but the approach is not.

Didn't you say Win9 would be here by the end of 2014? I remember thinking that is wildly optimistic. Apologies if it was not you.

That was just an internet rumor..

 

[AnandThenMan]

And DX12 is nothing like Mantle.

Really?

 

[f1sherman]

NVidia obviously wouldn't benefit as much as AMD from Mantle, because NVidia's DX drivers are more efficient

Only to a certain extent.
As witnessed by NV GPUs running better on AMD cpus than AMD own GPUs. And benefiting more from Windows 8.1.

But Mantle has raised the ladder much higher than that in terms of CPU performance.
More efficient DX 11.2 just doesn't cut it.

 

[ams23]

D3D is in Xbox, every DX11 GPU will support at least most of 12.0 That is 100% of the installed discreet base, + Xbone.

According to The Tech Report, AMD GPU's prior to HD 7xxx (ie. non-GCN GPU's) will NOT support DX12. On the other hand, all NVIDIA DX11 GPU's (including Fermi, Kepler, Maxwell) will support DX12.

 

[Gloomy]

okay dude

I need to know though... are the DX11MT and Nvidia bootlicking threads going to stop now?

 

[Carfax83]

Only to a certain extent.
As witnessed by NV GPUs running better on AMD cpus than AMD own GPUs. And benefiting more from Windows 8.1.

But Mantle has raised the ladder much higher than that in terms of CPU performance.
More efficient DX 11.2 just doesn't cut it.

You have to compare Mantle to DX11 multithreading, rather than just standard DX11.x..

Best case scenario in DX11 multithreading would result in 50% and greater performance gains in CPU limited situations. Mantle can get higher though, due to being more efficient and with a higher level of parallelization.

But it's not outrageously higher. DX12 multithreading should remove the major inefficiencies with DX11 multithreading, while simultaneously reducing overhead which will result in performance gains very similar to Mantle, but without the drawbacks of being tied to a particular architecture.

 

[AnandThenMan]

If most of the gains on NV hardware are going to come from more efficient MT techniques, then not much in the way of gains to talk about because Nvidia is already very strong here, right?

 

[VulgarDisplay]

According to The Tech Report, AMD GPU's prior to HD 7xxx (ie. non-GCN GPU's) will NOT support DX12. On the other hand, all NVIDIA DX11 GPU's (including Fermi, Kepler, Maxwell) will support DX12.

Fermi will be close to EOL by the time dx12 gets mainstream. That's a major win for nvidia?

 

[monstercameron]

at best dx12 might be easier to implement than mantle...then again this is pure speculation.

 

[f1sherman]

You have to compare Mantle to DX11 multithreading, rather than just standard DX11.x..

Yeah but that's not easy. Why?
Because who has bothered to fully implement DX11.x MT?

Yet in relatively short period 2 game devs did exactly that with Mantle.

Which tells me that either DX MT is not trivial to implement,
or gains/effort are not as clear cut as one would want to.

 

[Carfax83]

If most of the gains on NV hardware are going to come from more efficient MT techniques, then not much in the way of gains to talk about because Nvidia is already very strong here, right?

Right now DX11 MT is good, but it's not nearly on the same level as Mantle. DX12 MT should be on the same level as Mantle from a performance perspective (or a bit better perhaps as there are many other improvements across the board than just MT implementation) but without the drawback of being tied to GCN..

That doesn't mean that every IHV will get great gains from DX12 though, because performance will likely depend heavily on the quality of the drivers..

 

[monstercameron]

Right now DX11 MT is good, but it's not nearly on the same level as Mantle. DX12 MT should be on the same level as Mantle from a performance perspective (or a bit better perhaps as there are many other improvements across the board than just MT implementation) but without the drawback of being tied to GCN..

That doesn't mean that every IHV will get great gains from DX12 though, because performance will likely depend heavily on the quality of the drivers..

that isnt a drawback from a performance perspective.
that is literally what being close to the metal is all about.

 

[Carfax83]

Which tells me that either DX MT is not trivial to implement,
or gains/effort are not as clear cut as one would want to.

According to NVidia, DX11 MT is easier to do than manual threading. But developers were reluctant to use it because AMD didn't support it.

Also, because DX11 MT heavily depended on the drivers for performance, it took almost 2 years for NVidia to refactor their driver codebase, which was another blow to developers using it.

In any case, Mantle is obviously better than DX11 MT, I never denied that. But Mantle comes with a serious drawback, it's tied to GCN. So it was never going to replace DirectX, or OpenGL regardless, which makes it useless as far as becoming an industry standard.