There is a rumor about the Zen engineers helping on clock and efficiency for RDNA2, which would increase clock if the consoles are using RDNA2. It would be on 7nm+, which also help clock higher.
The CEO stated that some members from the Zen team had moved to RTG, and there was discussion about introducing some of the methodologies to the graphics tech.
No specific product or generation was specified as being the target, and the most recently disclosed optimized silicon is the Vega-based Renoir GPU.
Which part of RDNA1 has hardware acceleration for raytracing again?
That's right. There's absolutely no reason to think either console would be RDNA1, especially since based on the patents the RT acceleration is part of TMUs and I really doubt they'd mix'n'match TMUs of one generation with CUs of another
(only chance I can really see for RDNA1 in a console is Sony if by some miracle they're not using AMD RT)
That's much of what is made available for semi-custom clients. Cerny described a process where they were offered a menu of IP choices from current and future products, which could be put into their product.
Sony modified how the GPU L2 functioned with compute and used an expanded ACE front end for the PS4, and modified the SIMD hardware and ROP export path to include 2xFP16 and the ID buffer, respectively.
Microsoft's GPU included custom inclusions for legacy texture formats into the TMU hardware, as well as modifications for allowing for activating AF on legacy applications that didn't have it on Scorpio.
edit: about PS4 Pro, Sony never said it's "Polaris based", they said it uses "many new features from the Polaris architecture as well as several even beyond it".
There's few different possibilities, but either the 2xFP16 was trivial change or the gfx complex is Vega rather than Polaris. Think of AMD GPUs as Lego bricks, they have bunch of different bricks which are interchangeable and can work together (and to my understanding CUs aren't separate block, but rather part of bigger GFX block which would tie said block to specific architecture. Probably best recent example of this is the Intel "Vega", it's graphics block is Polaris, it's HBCC memory controller was first introduced in Vega and who knows which versions of vce, vcd, display controller and so on it includes
There's been some indications that the Pro's GPU is Sea Islands.
If you believe the github tests are valid information, their backwards compatibility tests specifically exclude certain modern instruction types from the PS4 and Pro modes that are available natively.
In other instances, either Sony specifically described how it brought in only certain next-gen features from Vega, or games that used RPM did not mention using any other useful architectural changes introduced after Sea Islands. If cross-lane operations and more effective scalar memory operations could have improved uniform calculations, I doubt an optimization team like the one used for Doom's Pro version would have ignored them.
Sony has been willing to customize its GPU beyond trivial changes, so I would say inserting RPM back into a prior generation ISA is non-trivial but not disruptive to the whole GPU.
