PlayStation 4 (codename Orbis) technical hardware investigation (news and rumours)

Since Cerny mentioned it I'll comment on the volatile flag. I didn't know about it until he mentioned it, but looked it up and it really is new and driven by Sony. The extended ACE's are one of the custom features I'm referring to. Also, just because something exists in the GCN doc that was public for a bit doesn't mean it wasn't influenced by the console customers. That's one positive about working with consoles. Their engineers have specific requirements and really bang on the hardware and suggest new things that result in big or small improvements.

 

Yes, of course. That's definitely possible. Possibly that its 6.5 but he just said over 5 for some random reason. That is, technically, possible. I won't argue that's not possible.

EDIT

Just to be clear, my smart ass sarcasm aside, I fully agree that is definitely possible. He doesn't give an exact number.

 

I almost forgot about this thread so I was asking this from the xbox thread.
I'm sure this would have been covered by now but is there any conclusion on the feasibility of Tiled Resources or something similar on PS4 via OpenGL yet? Is PS4's UMA not suitable for AMD's PRT?

 

PRT is a GCN feature. We have every reason to believe it's supported and the feature should already be exposed in libgcm. PRT is always useful because it cuts down unneeded memory access by the GPU irregardless of the system topology.

 

Is OpenGL the language for programming on the PS4, or is it some proprietary version (or extensions)? Isn't OpenGL somene extendable for this sort of thing?

I'm an artist, not a graphics programmer. So, this stuff is interesting to me, but not too directly effecting my work unless the tech lead yells at me to change something.

 

Yeah logically you would think so, I hope they do a demo on PS4 at some point preferably in a real game environment.

 

Most likely something along the lines of libgcm.

 

I wouldn't be surprised if PS4 supports OpenGL too in Sony's attempts to make the platform as accessible as possible. We've heard that devs can go low-level, but Sony aren't forcing that. Here's a rumour from 2012 on the idea of PS4 supporting OpenGL. I guess AMD will provide the drivers and devtools, so it's just a matter of connecting the lib to the OS.

 

edit

 

Not sure about the DirectX and OpenGL stuff mentioned in the thread, but PSSL is at least real.

http://www.psu.com/forums/showthread.php/313205-PSSL-PlayStation-Shader-Language-at-Gamescom2013

 

http://gamingbolt.com/mark-cerny-explains-the-ps4s-gpu-can-perform-asynchronous-complex-processes
mark-cerny-explains-the-ps4s-gpu-can-perform-asynchronous-complex-processes

 

the ps4 gpu can push 1.6 billion triangles - does this mean than it can push 1.6 billion polygons ?

 

I'm not sure what you're asking as a triangle is a polygon and it's the primary rendering element in a GPU.

 

like the dark sorcerer demo pushes 1 million polygons , so my question is can ps4 push 1.6 billion polygons ?

 

If the PS4 runs at 800MHz it can process 1.6 billion triangles/second but this number isn't useful for determining how many triangles you'll see on screen. You'll only be able to render this many if there's no more than one unique vertex per triangle and the number of vertex attributes is low enough that memory bandwidth doesn't become a problem. Plus the triangles must all be small enough that the rasterizer isn't a bottleneck.

Games engines don't just render one pass at full rate displaying all triangles on the scene. Some or all geometry is rendered multiple times to contribute to shadows or other effects. Plus you never achieve 100% efficiency out of all parts of the rendering pipeline. Even a contrived demo will only achieve 90+% efficiency.

 

Yes, in graphics speak, triangle = polygon.

At 1080p, 2 million pixels, one triangle per pixel, the most you could ever see would be 120 million per second. I guess we could supersample it x10 for 1.2 billion triangles a second...

 

thanx for the reply @3dcgi and @shifty
even if a demo can achieve 90% , then its very impressive . The quantic dream demo only used 1 million - by the end of the next gen if they can achieve 90% efficiency then it will avatar quality !

 

GDDR5 parallel read/write capacity

Reading the Elpida docs on GDDR5 at wikipedia, there is mention of parallel read/writes being possible. With DDR3 these operations are serialized, the question is even if the 8N burst of GDDR5 increases latency, how much the read/write parallelism will impact in practice?

 

But the sum doesn't add up to more than the physical peak performance of 5Gbit per pin. The PHY has a peak limit. Wouldn't the write cache be enough to hide latency?

 

You won't see Avatar quality this gen. By contrived demo I mean something that doesn't draw anything interesting just triangles splatted to a screen. When you add complicated shaders and other effects you'll never achieve the peak theoretical triangle rate over the course of an entire frame. You can achieve the peak rate in bursts when the content is suited for it.

Shadow mapping is an example where you could be limited by the triangle rate though these triangles are in addition to the scene triangle count because it means objects are being rendered multiple times.