DirextX 12 - no stream, updates

[Arkaign]

Zappykins said:

ICStats said:

Zappykins said:

Fusioncode said:

Zappykins said:

ICStats said:

VitroBahllee said:
I'm watching a liveblog of it now. This is going to really boost the Xbox One.

How will it do that?

They say DX12 is a console like API.  XB1 is already a console.  If it has a boost it would only be because their current SDK is bad.

Nah, it's not like that.  Think of it as like a super optimizing driver.  Only it will give you one platform that does what Steam wants their new OS to do, but with the years of experiences that developers have working on DirectX. It's like a new OS.

Xbox One should get at least a 20% GPU improvement according to what we saw today.  Perhaps significantly greater.

Unreal Engine 4 will get upgraded to work with DirectX 12.

It will be the new standard for is flexibility, scalability and power.  PC and Xbox One games will both benefit.

 

Can you please explain this? I'm curious as to why you think that will happen. 

Well, assuming Xbox One will  at least some of the benifit of a 50% optimization, but probably already is ahead of PC's there.   But even if it doesn't, they stated a 20% reduction in GPU render time per frame, or something to that effect.

Mantle is supposed to give a 20% improvement at well.  It's a bit like mantle.

So I went with a conservative estimate of 20%.  The baseline of the GPU.  However, the scaling across the 8 core CPU might result in greater improvements.

I can't read anything on the slide you attached about a GPU side improvement.

What Mantle does it it improves framerates when you have a powerful GPU and weak CPU, because the CPU becomes the bottleneck.  I've never heard of any actual GPU side speed up per-se.

Also XB1 already has some features for multithreaded rendering, and pre-baking command lists so it already has a lot - if not all - of the gain DX12 will give.

It's also hard to say if CPU is the bottleneck in the XB1, since PS4 has basically the same CPU.

Well, a couple things, Microsoft has said the CPU was the bottle neck for consoles.  Might be spin but that's what they said.  I think they do believe that.  It has some different co processors and stuff that the PS4.  They are really good at squeezing power out of phones, writing popular operating system, business software, and games.  So they designed the Xbox One to do what they wanted it to do within a price.

And in the talk they said 20% GPU improvement on same hardware (or to that effect) - things would render and have 20% of the time left over – during the talk.  Wish I had the slides that were clear.   I get the other parts, like CPU enhancement not apply, but why would you think the GPU improvement would not apply to the Xbox One?

For the primary reason that the low-hanging fruit in DX11 (PC version) is the CPU bottleneck with regards to draw calls, which inhibits the GPU from working more efficiently. IOW, when you transition more of that to low-level API operations, the CPU becomes less of a bottleneck, and the GPU can work more efficiently at it's full capability.

The PS4 and XB1 have fairly weak CPUs. No two ways about that. Still, they pulled off Forza 5 (albeit with some downgrades, but still damned good work really) with a weak CPU and midrange GPU. The performance is a good bit better than a PC with similar specs would be capable of with DX 11, showing that what the XB1 architects said about the console pre-launch was true : that they already had optimized the XB1 SDK to allow for low-level hardware access.

Additional tweaks can be made, but it's not going to be like Mantle with a transition from bottlenecked API to low-level API. It's going to be going from a low-level API to another low-level API, with hopes of gaining some efficiency somewhere. At the same time, the hard limits are there with throughput, shaders, processing bandwidth, and so on. So perhaps they can go from 90% efficiency to 96% efficiency (obviously guesstimation, but you get the idea).

On the other hand, figuring out tricks, helping devs really get on board with optimizing engines to work with XB1, all that stuff can be great. They can figure ways where they're not technically moving more data, but because of how it's laid out and prioritized, it looks substantially better.