Why Sony should also use a Cell Processor for PS5 (x86+Cell coprocessor)

[Trumpstyle]

Pemalite said:

Trumpstyle said:

"Moving to a different CPU - even if it's possible to avoid impact to console cost and form factor - runs the very high risk of many existing titles not working properly," Cerny explains. "The origin of these problems is that code running on the new CPU runs code at very different timing from the old one, and that can expose bugs in the game that were never encountered before."

Cerny is right on the money there. Game engines on consoles sometimes have a "tick rate" that is tied to the clock rate/performance of the CPU.

It's an extremely rare occurrence... And I would be surprised if any modern game/game engine even takes that approach in the modern era anymore... Besides, such issues would have become apparent on these mid-generation consoles refreshes anyway.

Trumpstyle said:

To me this is clear. Using ryzen cpu will break backwards compatibility. That's why I'm guessing ps5 will have 4 ryzen cpu cores + 8 jaguar cores if they go for BC.

And... Disagree with you here.

From a hardware feature set point of view, Ryzen should be fully backwards compatible with Jaguar from an ISA standpoint, so the real caveat is entirely performance based.
CPU's these days have a varying degrees of clock-rates that they can operate at to meet various performance/power targets.
There are dozens of ways you can influence that to meet backwards compatibility goals, possibly even use the power of abstraction.

Next-Gen is highly unlikely to use Ryzen CPU cores, well... Not the Ryzen we have today anyway.

 

vivster said:

Trumpstyle said:

My guess is that console games for ps4 are specifically designed to work with 6 jaguar cores. But this what Mark cerny said about this subject when talking about ps4 pro:

But surely x86 is a great leveller? Surely upgrading the CPU shouldn't make a difference - after all, it doesn't on PC. It simply makes things better, right? Sony doesn't agree in terms of a fixed platform console.

"Moving to a different CPU - even if it's possible to avoid impact to console cost and form factor - runs the very high risk of many existing titles not working properly," Cerny explains. "The origin of these problems is that code running on the new CPU runs code at very different timing from the old one, and that can expose bugs in the game that were never encountered before."

 

To me this is clear. Using ryzen cpu will break backwards compatibility. That's why I'm guessing ps5 will have 4 ryzen cpu cores + 8 jaguar cores if they go for BC.

This says nothing without deeper knowledge of how the majority of games for the console are programmed. It might be solvable with a simple patch and if it's connected to clock speeds it should be easy to have older games run in a legacy mode where the PS5 just locks it at lower speeds.

The tools that are used to program for PS4 should be old and standardized enough to make any software issue solvable without resorting to legacy hardware. I don't really think it's possible to program a game so statically that a newer processor can actually break it. Especially considering that the vast majority of games runs on multiple platforms and as such shouldn't be hardcoded to specific hardware platforms.

This discussion is getting slightly out of my wheelhouse. But what Cerny was referring to had nothing to do with clock rate or clock speed. What he meant was that newer cpu architecture run game codes at different timings than old ones. This is way for cpus to increase ipc (performance per ghz). But because game code running a bit differently on newer cpu architecture this can cause bugs when running ps4 games. 

This is why Cerny says this can make many titles not working properly and not "an extremely rare occurence" as you put it Pemalite.

But again this is a little above my knowledge. So I'm probably about 90% right here.