AMD @ GDC: Partnership with MS next-generation graphics.

[monstercameron]

The DirectX dev blog puts to rest all of the conjecture surrounding DX12's relationship, or lack thereof with Mantle..

Basically, DX12 uses a similar, but vastly improved multithreading technique as DX11 multithreading, which uses command lists.

Mantle is nothing like that, so DX12 is completely different from Mantle and is actually more similar to DX11; which is what you'd expect considering it's supposedly compatible with DX11 hardware...

mantle is also relatively compatible with dx11 [they use the same shading IL], how else would it only take 2 man months to "port" games to mantle?

 

[f1sherman]

mantle is also relatively compatible with dx11 [they use the same shading IL], how else would it only take 2 man months to "port" games to mantle?

the poorest of the poor among game developers would have already gotten that additional man(1) and gave him 2 paychecks,

if it was really 2 man months

 

[OCGuy]

mantle is also relatively compatible with dx11 [they use the same shading IL], how else would it only take 2 man months to "port" games to mantle?

What was ported in 2 months?

 

[monstercameron]

the poorest of the poor among game developers would have already gotten that additional man(1) and gave him 2 paychecks,

if it was really 2 man months

seriously? 2 man months doesn't mean 2 months.

 

[Carfax83]

mantle is also relatively compatible with dx11 [they use the same shading IL], how else would it only take 2 man months to "port" games to mantle?

Mantle shares some similarities with DX11, but when it comes to how multithreading is handled, it's completely different.

Multithreading in DX11 (and in DX12) is mostly handled by the GPU driver. With Mantle, there aren't any driver threads at all.

 

[ASM-coder]

Mantle is nothing like that, so DX12 is completely different from Mantle and is actually more similar to DX11

Except Microsoft themselves use the term "closer to the metal."

 

[f1sherman]

seriously? 2 man months doesn't mean 2 months.

It doesn't?

OK how about 3 times that?
That's 6 monthly paychecks.

Still doesn't change my point of being embarrassingly cheap to implement, yet only few are doing it.

 

[ASM-coder]

It doesn't?

OK how about 3 times that?
That's 6 monthly paychecks.

Still doesn't change my point of being embarrassingly cheap to implement, yet only few are doing it.

Oxide's Dan Baker in a Maximumpc interview:

Baker: APIs come and go. Once you support more than one, it's pretty easy to support a dozen–assuming there is parity in the hardware features, and assuming you don't have to rewrite your shaders in an entirely different language. If you release a title right now, you would end up with likely six paths. An Xbox360, a PS3, a PS4, a Xbox One, a DX9, and a DX11. For us, the graphics system is just a module that talks to the API. All we did for Mantle was replace the D3D module with a Mantle one. It's about 3,000 to 4,000 lines of code for the Mantle version, which took me personally about two months to write. In terms of support, at least for us, it wasn't terribly difficult.

 

[f1sherman]

I know... I've read that before.
So IT IS 2 MONTHS!?

monstercameron says it isn't.

 

[ASM-coder]

I know... I've read that before.
So IT IS 2 MONTHS!?

Like anything... I suppose it depends. His demo may have been small, and he knows the code pretty well, but I think Johan quoted a similar amount of time, and I doubt the Frostbite 3 engine is trivial.

 

[monstercameron]

I know... I've read that before.
So IT IS 2 MONTHS!?

monstercameron says it isn't.

I also read this before

 

[selni]

seriously? 2 man months doesn't mean 2 months.

Isn't that exactly what it means? One person working for two months (or two working for one month each etc, but it's not always possible to divide like that of course).

 

[monstercameron]

Isn't that exactly what it means? One person working for two months (or two working for one month each etc, but it's not always possible to divide like that of course).

AFAIK this is for billable hours, one only works so many hours per day.
2 man months assuming all hours are billable would mean 1 man working day and night for 2 months.

also if my math is correct -which is often not the case- then for 1 man working that long can be up to 6 months if we assume 8 hour days.

 

[Despoiler]

Man hours gives you pure labor. It does not tell you how much time you aren't working on something ie breaks, lunch, sleeping, etc. So 2 man hour months is actually some value higher than 2 in calendar time.

 

[PPB]

Repi isn't leaving much to speculate with his tweets either

If he still has his account here, would be lovely to hear something from him on this subject

 

[VulgarDisplay]

Man hours gives you pure labor. It does not tell you how much time you aren't working on something ie breaks, lunch, sleeping, etc. So 2 man hour months is actually some value higher than 2 in calendar time.

It could be far less than 2 months if more than one person is working on it.

 

[monstercameron]

It could be far less than 2 months if more than one person is working on it.

assuming that the workload can be properly parallelized a la cpus or gpus...

 

[Despoiler]

It could be far less than 2 months if more than one person is working on it.

Yah definitely, but we know Dan is the only one that worked on it though. For the Forza DX12 demo we have no idea if one person or a team worked on it. 4 man hours months could have been a calendar month like you pointed out.

 

[OCGuy]

nvm

 

[OneOfTheseDays]

Mantle has no future because no graphics vendors outside of AMD will ever get onboard.

DirectX12 is the future and if they can realize performance gains that approach what Mantle has shown on a broad range of graphics cards then everyone profits, not just AMD users.

 

[TreVader]

Mantle has no future because no graphics vendors outside of AMD will ever get onboard.

DirectX12 is the future and if they can realize performance gains that approach what Mantle has shown on a broad range of graphics cards then everyone profits, not just AMD users.

DX12 has no future because no game developer outside of Bungie will ever get onboard.


Mantle is the future and if they can realize performance gains that approach what DX12 has not shown across a broad range of graphics then everyone profits, except nvidia.

 

[3DVagabond]

the poorest of the poor among game developers would have already gotten that additional man(1) and gave him 2 paychecks,

if it was really 2 man months

AMD isn't offering support to all the poorest of poor devs at the moment. They are taking on devs at the rate they can handle it. Crytek, most recently. I'd say the smaller devs are going to be waiting a while before they get access.

 

[3DVagabond]

Repi isn't leaving much to speculate with his tweets either

If he still has his account here, would be lovely to hear something from him on this subject

Yes, and hopefully people won't be able to attack him again accusing him of trying to convert the thread to a marketing campaign simply by offering us some info. I'd love to have one person in a thread about Mantle who actually knows what he's talking about for a change.

 

[antihelten]

Mantle shares some similarities with DX11, but when it comes to how multithreading is handled, it's completely different.

Multithreading in DX11 (and in DX12) is mostly handled by the GPU driver. With Mantle, there aren't any driver threads at all.

I'm no expert when i comes to graphics drivers, but if you look at the directx developer blog here: http://blogs.msdn.com/b/directx/archive/2014/03/20/directx-12.aspx, specifically at the first figure which lists all the stuff running on each thread, you'll notice that with dx12 the KM driver or kernel mode driver completely dissappears.

I wonder if this isn't in fact what DICE calls the driver thread, which isn't present in Mantle either? If not, what is it exactly, and why does it go away completely with DX12?

 

[Silverforce11]

Repi isn't leaving much to speculate with his tweets either

If he still has his account here, would be lovely to hear something from him on this subject

Pretty much confirms it, if Johan is saying he had a direct hand in DX12 design then its basically multi-vendor Mantle. Kudos to MS for pushing it, all gamers will benefit with alleviating CPU bottlenecks, few things are worse than fps chokes during intense scenes in games.