Next Generation Hardware Speculation with a Technical Spin [2018]

Doesn’t the PS4 already rely on that for a sync computers it can snoop the CPU caches? Seems that would be complex or rather inefficient to do over a traditional motherboard.

 

*cough* https://forum.beyond3d.com/posts/2041814/

 

I wonder if Sony/AMD will use Infinity Fabric technology as the tie (interposer) between the CPU and GPU, instead of a traditional PCI bussing system. Seems plausible (see below); maybe memory and other communication controllers as well.

https://en.wikichip.org/wiki/amd/infinity_fabric

 

It features on PS4, but is it any use and are devs/games befitting? Or is it a nice idea in theory but with no real practical application in actuallity? With GPUs able to create their own jobs, how much CPU <> GPU communication is actually needed?

 

I think another benefit is decoupling of architecture and technology timelines, especially if they want launch date flexible. Imagine one chip on 7nm and the other on 7nm+, or an early Zen 3 variant if they throw all custom circuitry on the GPU die or vice versa.

 

If they went discrete gpu, what would the RAM target be? I can't imagine it being 4GB of VRAM, so probably 6GB or 8GB? Then 8 or 12GB of RAM?

 

I don't think there will be a split memory configuration. I believe both GPU/CPU will access to the same pool of GDDR6.

 

Unified memory was top of the request list from devs when Sony did the PS4 "what do you want?" tour. Is that really going to be the case for PS5/XB2?

No one will ever need more than 8GB of VRAM will they?

Said with full knowledge of the many times in computing people have said no one will every need more than x of something.

 

8c/16t not really beast if theres 32c/64t @4.5ghz already now.
Dunno about the gpu.

 

Yah, I guess in my head I've gotten used to APUs in the console space, but 360 had a unified pool and it was a discrete gpu.

 

Now that we are at it, what happened to HSA?

 

A 8c/16t CPU even in the PC gaming space is way more than enough (and forcible future) to run today's and tomorrows games. Heck, 4c/8t with nice clocks can run today's PC games without much difficulty.

 

Even if the CPU is 8c/16T, I expect it to be clocked lower and with a smaller cache than the PC counterparts so I don't think it will be a beast. but very capable nonetheless.

I think they'll only dedicate at most 1/3 the power and silicon budget for the CPU.

 

Yeah. 25.6 GB/s bandwidth from GPU to main memory and then the GPU feeds the CPU through a 22 GB/s link. So all memory traffic travels through the GPU's memory controller.

Be interesting if we see a return to something similar to that.

Regards,
SB

 

Zen CCXs are already connected to on-die and remote memory controllers with Infinity Fabric. If 7nm economics dictate smaller dies and decoupled CPU-GPU, I don't see an issue with using one remote CCX. Unless we're assuming an SoC would have provided a faster interconnect. However a smaller GPU die may limit memory interface width

The bespoke CPU die could also include the southbridge and a cheap RAM interface for the OS like PS4 pro. Or even a larger pool for gaming workloads. I'm not convinced a unified memory pool is necessary if neither are constrained.

 

Separate dies sounds like a good idea only if a single chip would be too large. Which isn't very plausible for a $400-$500 console, unless the yield will become a big enough problem on 7nm that the overhead of having two chips is worth the gain in yield?

 

Discrete GPU setup may be used only for early devkits. Who knows how this insider info was obtained, maybe the source had access only to devkit info.

 

What's the credibility of this insider?

 

He's on the internet. ?

 

He's inside the internet.