gfx analysis of e3 demo

[Griffith500]

In terms of the raw frame setup, things like going through lists and culling geometry might take more CPU time, but it's just a different balance that a specific Neo / Scorpio version would have to find.

If they're concerned that the game logic won't run at twice the rate without a performance hit, that might be the case for some games. But if you put the effort in to either decouple the graphics and logic (really, it should be the norm) and / or offload some of the logic to the GPU, you're laughing.

It's almost as if DF is expecting the very people who can make game engines work on the current consoles to not be able to do the same on these lightly fettled ones.
It's simply a matter of how much time each dev can devote to it. Most will simply add more particles, or similar, but several will do interesting things, no doubt.

 

[7HO]

According to Digital Foundry

They are wrong.

The GPU is equivelent to an R7 265, that is well documented. You can easily search the performance of the R7 265 and look at videos of how well it performs, you can check out Youtube videos as well, what you will find is the PS4 actually perfoms better than an R7 265 combined with a top tier CPU. On the other hand benchmarks of the PS4 CPU show excellent performance. You can be sure that the CPU is not holding back the performance of the GPU.

But as I said before and others have said form the issues the PS4 has you can clearly see the GPU is struggling and not the CPU however I would say they are pretty well matched in the PS4.

As for the comments about the NEO, given the recent comments by Jim Ryan and a lot of reading between the lines I am speculating that the rumoured specs of NEO are not accurate and I really wouldn't be surprised if they were leaked intentionally. I'm looking forward to when the specs are known not rumoured.

 

[Tornado]

That's called integrated graphics.

No, it isn't. Real-time 3D graphics rendering existed long before GPUs did, and CPU designs have already existed that were capable of rendering realtime 3D graphics with greater efficiency than a traditional x86 processor even before things like Jaguar in the PS4. That was supposedly even Sony's original plan for the PS3.

The PS4 is limited by its graphical power, not computational power, hence why people can run second gen i7 processors on a GTX1080 without bottlenecking.

The power discrepency between a second generation i7 and Jaguar is even greater than Jaguar and a high clocked i3.

 

[Fgame]

They are wrong.

The GPU is equivelent to an R7 265, that is well documented. You can easily search the performance of the R7 265 and look at videos of how well it performs, you can check out Youtube videos as well, what you will find is the PS4 actually perfoms better than an R7 265 combined with a top tier CPU. On the other hand benchmarks of the PS4 CPU show excellent performance. You can be sure that the CPU is not holding back the performance of the GPU.

But as I said before and others have said form the issues the PS4 has you can clearly see the GPU is struggling and not the CPU however I would say they are pretty well matched in the PS4.

As for the comments about the NEO, given the recent comments by Jim Ryan and a lot of reading between the lines I am speculating that the rumoured specs of NEO are not accurate and I really wouldn't be surprised if they were leaked intentionally. I'm looking forward to when the specs are known not rumoured.

The PS4 is cpu limited, there are games on the Xbox that run faster when AI is involved, just because it has 1.75GHZ compared to PS4 1.6ghz, and the PS4 gpu is 50% more powerful than the Xbox. Xbox struggles to get to 1080p where PS4 is better.

 

[7HO]

The PS4 is cpu limited, there are games on the Xbox that run faster when AI is involved, just because it has 1.75GHZ compared to PS4 1.6ghz, and the PS4 gpu is 50% more powerful than the Xbox. Xbox struggles to get to 1080p where PS4 is better.

Can you not see that you are making everyones point with this comment.

The CPU is related to AI performance in your post but the Xbox which has a better CPU isn't able to match the PS4's graphic performance.

 

[Fgame]

Whose points?
Digital foundry are saying cpu is needed for better frame rate.
If the AI calls upon the cpu, it can reduce the frame rate. Other effects also call upon the cpu.
My point with the PS4 50% more powerful gpu. is that it doesnt show in many games (frame rate), apart from comparing resolution. Which is what DF said it was good for. Which is why I say it looks like both Sony and Microsoft are going for 4k resolution rather than frame rates as a priority.
So it seems like with the NEO even with over 2x Tflops performance. It wont be enough to make PS4 30fps games run at 60fps. But it will make games run in 4k at 30fps I think. That's a guess. But I am not sure, as this may conflict with the supposed Sony developer rules governing frame rate performance. We will have to see.

 

[Griffith500]

Whose points?
Digital foundry are saying cpu is needed for better frame rate.
If the AI calls upon the cpu, it can reduce the frame rate. Other effects also call upon the cpu.
My point with the PS4 50% more powerful gpu. is that it doesnt show in many games (frame rate), apart from comparing resolution. Which is what DF said it was good for. Which is why I say it looks like both Sony and Microsoft are going for 4k resolution rather than frame rates as a priority.
So it seems like with the NEO even with over 2x Tflops performance. It wont be enough to make PS4 30fps games run at 60fps. But it will make games run in 4k at 30fps I think. That's a guess. But I am not sure, as this may conflict with the supposed Sony developer rules governing frame rate performance. We will have to see.

AI will run on the GPU just fine.

 

[Fgame]

AI will run on the GPU just fine.

Well you know of skills that no developer for consoles has learned.

 

[Griffith500]

Well you know of skills that no developer for consoles has learned.

Not true.

It "simply" requires a different, data-driven approach instead of a sequential logic one. Most of the difficulty is actually with "race conditions" (modifying the same output multiple times, and not always in the same order), not the branching "if - then" crutches, which can be designed out with some logical skill and rethinking of the overall behaviours.

The simple semi-solution to race conditions is what is used in graphics already: double buffering. Functional programming styles (not necessarily functional languages per se) help as well, which are more developed in systems and "cybernetics" derived subjects, e.g. AI proper.


People forget that game AI today is written in a way that is easy to program for the hardware it will run on. It only takes the realisation that the hardware is different to learn to approach the algorithmic breakdown of the concepts or "problems" in a different way. Just the way it did with hardware graphics acceleration 20 years ago. Mathematics is full of symmetries.

These are skills that for some reason aren't required in (mainstream) games development (any more), but are (still) well developed elsewhere. That can change in a matter of months. Evolve or die out.

Of course, if someone makes an SDK or toolkit, everyone's laughing.


EDIT: And if I wanted to be a pedant, the AI code will run unaltered just fine as well. Just not very efficiently.

 

[Fgame]

The method you are suggesting is not currently viable or used for console gaming to prioritise performance. Maybe in the future, but at the moment clock speed of the cpu is king of the frame rates and gpu the resolution it seems.
Developers are being quite slow in making use of gpu for frame rates, otherwise the PS4 would be leagues ahead of the Xbox. They appear to prefer to use the extra PS4 gpu power to make 1080p and have the xbox at either 900p or continuously variable resolution.

 

[Griffith500]

The method you are suggesting is not currently viable or used for console gaming to prioritise performance. Maybe in the future, but at the moment clock speed of the cpu is king of the frame rates and gpu the resolution it seems.
Developers are being quite slow in making use of gpu for frame rates, otherwise the PS4 would be leagues ahead of the Xbox. They appear to prefer to use the extra PS4 gpu power to make 1080p and have the xbox at either 900p or continuously variable resolution.

How will it change in future? It's either possible, or it's not.

The architecture is not going to change drastically any time soon, aside from things like homogeneous code on heterogeneous hardware (e.g. AMD's HSA) which will make traditional parallel "problems" like cache coherency a thing of the past. Oh wait, the current consoles already have shared memory and proto-HSA features...


Developers are slow to do anything different from what they already do, because doing something different leads to uncertainty because uncertainty means money lost and money lost means publishers walk elsewhere. This is where MS and Sony are really instrumental in making transitions easier, e.g. by offering SDKs etc. Remember when Sony updated their SDK a year or so ago to include GPGPU features?

There is also the small issue of people's attitudes towards GPGPU itself, such as "it's not possible". Which is patently false, rooted in generalisations and reasoned against past visions of hardware (and software), not its current state, and simply taken for granted rather than investigated on an individual basis.


Also, the CPU has an influence on framerate, but so does the GPU - probably moreso in most cases these days.