Current Generation Hardware Speculation with a Technical Spin [post GDC 2020] [XBSX, PS5]

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Going by MS's series S interview with Digital Foundry, MS really does seem pretty confident that Sony don't have VRS.

https://www.eurogamer.net/articles/digitalfoundry-2020-xbox-series-s-big-interview

Jason Ronald stepped up to tackle this one: "The real critical tentpoles when we think about RDNA 2 are DirectX ray tracing with hardware acceleration, mesh shader support, which we have full support for, and then obviously, variable rate shading."

So going by the stated Gears 5 benefits, that could be another 5 ~ 12% performance for series X relative to the flops advantage that MS would like us to think they have.

Seems particularly useful for the Series S, what with it's 4 TF and all.
 
Are all of those hardware accelerators scaling with GPU compute units? Or would there be a case were Series S could have the same dedicated hardware power?
 
New Going by MS's series S interview with Digital Foundry, MS really does seem pretty confident that Sony don't have VRS.


Some of Matt Hargett's comments on VRS:


One of the latest videos from RGT claims that gamedevs have been telling them that Sony's VRS implementation is intertwined with the custom Geometry Engine. Perhaps the shading rate in the PS5 depends directly on geometry LOD, and both depend on Z values.
Add these to the fact that Sony filed more than a bunch of patents related to foveated rendering and they definitely have something performing those or similar tasks.


What the PS5 doesn't have for sure is the RDNA2 / Navi 2x standard VRS implementation for DX12 games, though why Microsoft keeps trying to make a big deal out of it is up to anyone's guess.
Perhaps they're just banking on the fact that Sony decided not to talk about it.
 
We'll know much clearer by the weekend the percentage difference between them. Hot air on functionality could be from either (both?) of Sony/Microsoft.

I'll hazard a guess at 15-20% in favour of Series X. Happy to be wrong in favour of either console, since that difference is a bit boring.
 
What 3P XS game uses VRS, dirt5?
Be interesting if can detect it on PS5 version. Even if it doesn't use it, that doesn't mean PS5 definitely doesn't have it in hardware, could be api maturity issue.
 

He's not saying in either of those that Sony have VRS, though. He's saying GE is more important (both MS and Sony have a GE), that VRS affects performance on a per game basis, and that Sony did a great job talking about their best features.

All of which are probably true, but none of which mean Sony has VRS or a direct equivalent. At this point, he could as easily be trying to avoid that particular comparison as imply it's there.

One of the latest videos from RGT claims that gamedevs have been telling them that Sony's VRS implementation is intertwined with the custom Geometry Engine. Perhaps the shading rate in the PS5 depends directly on geometry LOD, and both depend on Z values.

Well I guess we'll see exactly what Sony have or don't have in time. But I don't trust RGT to filter legitimate information from clickbait rubbish, as it's served him well not to.

BTW do we have a PS5 die shot yet? I can't find one. That should tell us in definite terms about the CPU L3 thing....

Add these to the fact that Sony filed more than a bunch of patents related to foveated rendering and they definitely have something performing those or similar tasks.

Foveated rendering is not really a substitute for fine grained variable rate shading; it's more like variable sampling rate / resolution based upon the area of screen space you're rasterising into (and then fixed shading based on those samples). And you don't know where someone is looking on a TV, which makes optimal use more difficult. You could maybe guess based on what's going on screen (e.g. user is probably looking at what they're shooting at or where enemies are moving), but it's really VR with eye tracking where it'd produce best results.

Mesh shaders / primitive shaders, multiple render targets and / or VRS should combined or individually give you various way of implementing stuff like this. Which isn't to say that Sony don't have customisations that could accelerate, say, the geometry side of things and allow the use of a single render target for all resolutions.

What the PS5 doesn't have for sure is the RDNA2 / Navi 2x standard VRS implementation for DX12 games, though why Microsoft keeps trying to make a big deal out of it is up to anyone's guess.
Perhaps they're just banking on the fact that Sony decided not to talk about it.

Or perhaps Sony don't have anything directly comparable, and MS know it? Either way, it's not make or break and I don't think anyone playing the games would really care. It's more of a detail things for places like this where a few percent are interesting ... and also a marketing point for slick videos with unrepresentative CGI mashups and high energy "aspirational" music ... :sleep:
 
Some of Matt Hargett's comments on VRS:


One of the latest videos from RGT claims that gamedevs have been telling them that Sony's VRS implementation is intertwined with the custom Geometry Engine. Perhaps the shading rate in the PS5 depends directly on geometry LOD, and both depend on Z values.
Add these to the fact that Sony filed more than a bunch of patents related to foveated rendering and they definitely have something performing those or similar tasks.


What the PS5 doesn't have for sure is the RDNA2 / Navi 2x standard VRS implementation for DX12 games, though why Microsoft keeps trying to make a big deal out of it is up to anyone's guess.
Perhaps they're just banking on the fact that Sony decided not to talk about it.
I'm still convinced the PS5 doesn't have anything special about the Geometry Engine. When Cerny mentioned Geometry Engine it was in reference to comparing the PS5 to the PS4. AMD has called their fixed function geometry hardware "Geometry Engine" for awhile now and one would assume that the architectural changes in RDNA 2 bring with it a new geometry engine versus was what in the PS4. Hargett is also describing the Geometry Engine as doing what AMD's famed "primitive shaders" were trying to do and primitive shaders could be viewed as AMD's precursor to their mesh shader implementation.

There's a non-zero chance that Sony ratified the PS5 hardware before AMD got mesh shaders working so the PS5 might simply have an older iteration of the geometry engine.
 
I'm still convinced the PS5 doesn't have anything special about the Geometry Engine. When Cerny mentioned Geometry Engine it was in reference to comparing the PS5 to the PS4. AMD has called their fixed function geometry hardware "Geometry Engine" for awhile now and one would assume that the architectural changes in RDNA 2 bring with it a new geometry engine versus was what in the PS4. Hargett is also describing the Geometry Engine as doing what AMD's famed "primitive shaders" were trying to do and primitive shaders could be viewed as AMD's precursor to their mesh shader implementation.

There's a non-zero chance that Sony ratified the PS5 hardware before AMD got mesh shaders working so the PS5 might simply have an older iteration of the geometry engine.

Be glad theres still people going with secret sauce theories this day and age. Its something i miss from the early 2000's.
 
Be glad theres still people going with secret sauce theories this day and age. Its something i miss from the early 2000's.
Geometry Engine has blast processing.
While I see what Hargett is saying, I'm not sure that I follow his "compute vs cycles" comparison. If you are "saving cycles", you are saving compute. And if you are looking at 2 systems with similar compute, but one is narror with a high clock, and the other is wider with a slower clock, every cycle you save on the one that's clocked slower is proportionally larger. 1/1.825 is bigger than 1/2.23
 
Yeah this guy doesn't know what he's talking about. Blast processing indeed.
I mean, he does. If you are culling polygons early, you don't have to run shaders on those surfaces at all. But I fail to see how mesh shaders don't do this, and how Geometry Engine is better at it, and if you have both early culling and VRS, wouldn't that be the best? Most mainstream GPUs have been doing similar work since... Well, I remember the first Radeon having it as a feature. And I think it was the 8500pro or 9700 I had that could finally match my PowerVR Kyro in the shadow puppet demo a demo designed specifically to show off the surface culling capabilities of a tile based differed renderer using unrealistic levels of overdraw. PowerVR were culling surfaces since 1996 when everyone else was just brute forcing more fillrate, and everyone else has been leveraging surface removal to get even better performance since the early 2000s.

I know this is from nVidia and not AMD, but since mesh shaders are part of DX12U, I think it's safe to assume they are functionally identical between the vendors, even if the implementation and performance may differ.
https://developer.nvidia.com/blog/introduction-turing-mesh-shaders/
The Turing architecture introduces a new programmable geometric shading pipeline through the use of mesh shaders. The new shaders bring the compute programming model to the graphics pipeline as threads are used cooperatively to generate compact meshes (meshlets) directly on the chip for consumption by the rasterizer. Applications and games dealing with high-geometric complexity benefit from the flexibility of the two-stage approach, which allows efficient culling, level-of-detail techniques as well as procedural generation.
Red+bold+underline is mine. Efficient culling is part of the mesh shaders' function.

And again, regarding wasting cycles, each cycle on Series X is capable of more compute vs each cycle on PS5. So if you are trying to optimize for Series X, it seams reasonable that if you save more cycles, you get back more compute. Well, I guess that's true on PS5 also, since compute is achieved by the width of you pipeline multiplied by your clock rate. So you would still be saving compute. I don't know, maybe I'm missing something. Maybe GE is something completely new.
 
What the PS5 doesn't have for sure is the RDNA2 / Navi 2x standard VRS implementation for DX12 games, though why Microsoft keeps trying to make a big deal out of it is up to anyone's guess.
Perhaps they're just banking on the fact that Sony decided not to talk about it.
You should read the full interview with DF. DF rightfully so said there are legal issues for making a false statement and Xbox being the only console with full RDNA2 has to respect the laws and perhabs even AMD had their say in that messaging. Xbox didnt lie and hoped Sony doesnt talk about this. In fact Sony could sue them, if it were a lie.
 
You should read the full interview with DF. DF rightfully so said there are legal issues for making a false statement and Xbox being the only console with full RDNA2 has to respect the laws and perhabs even AMD had their say in that messaging. Xbox didnt lie and hoped Sony doesnt talk about this. In fact Sony could sue them, if it were a lie.
Sure. But if PS5 has RDNA3 geometry engine, then it's RDNA2.5 and it's indeed not full RDNA2.
 
Sure. But if PS5 has RDNA3 geometry engine, then it's RDNA2.5 and it's indeed not full RDNA2.
PS5 has RDNA5. Just as realistic as 2022 RDNA3. I think those believing in RDNA3 should rewatch the Deep Dive by Cerny and what he thinks determines a succesfull partnership with AMD.

Quote myself:
RDNA3 comes out in 2022. Says everything you would need to know about these speculations. Addionally Cerny said during the deep dive their coloberation with AMD worked, if GPU launching in the same time frame have similar features.
 
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