PlayStation 4 (codename Orbis) technical hardware investigation (news and rumours)

Not to nit pick, but technically he said that in his opinion there's no clear bottleneck in the system design. Excessive memory wouldn't be a bottleneck, it would be an excess. Having more memory than needed wouldn't bottleneck anything, while not having enough would. Excessive memory only bottlenecks BOM.

 

I don't think devs would call any amount of RAM excessive. Any increase means less swaps with the hard drive. And with 50GB game discs, you can bet there's always content to swap from the HDD.

I'm just more excited that the pool is unified. The less technical hoops a 3rd party has to jump through to get peak performance, the quicker we get great 3rd party games. I expect a lot out of Watch Dogs and ACIV, for instance.

 

Well, if the memory and its bandwith were to be so massive that the rest of the system wouldn´t even be able to completely make use of it, then the amout of memmory would have made everything else a bottleneck. Now, given developers have always bitched about amout of memory and bandwith on every console hardware generation I can remember, I´m sure 8Gigs at 178GB/s won´t be anything close to that unbalancing.

 

It is balanced at 25.9 fps. Very good I'd say! Wonder how long it will take before they actually really reference 8Gigs per frame.

 

Why would they ever touch 8GB per frame? That's totally unrealistic, even unreasonable. While I'm sure contrived schemes could be cooked up to make it happen, I can't imagine a single, non-gimmicky legitimate need for that. In any case, it would be a very low framerate as memory access typically isn't 100% efficient...

 

Sounds like marketing speak to me and not particularly meaningfull to be fair. Are we to believe that had ps4 featured 24 CU's it would no longer have been as balanced or efficient? Or what if the bandwidth had been 240GB/s or it only featured 6GB RAM this is somehow less balanced? The specs of Orbis are what they are because that's the best sony could get for what they were willing to pay. Its not like 18 CU's + 8 jaguar cores plus 8GB RAM is some some magical perfect balance of components for maximum efficiency.

 

Framerate is always a bottleneck. There's stuff you can do at 30fps you can't do at 60fps.

 

100% agreed. Actually I'm still living the '8GB IS an excess' mode. But I guess for now this excess at least results in less drive wear off.

 

Yeah I fully agree with that. Within the limitations of a single apu it actually is a VERY nicely balanced and efficient design.

 

I don't think 8 is excessive. Part of that will be for the OS (probably 1gb) leaving 7 accessible at probably 4-5 gb/frame at 30fps. So a dataset of 4-5gb with the rest being devoted for cache.

 

He's saying they couldn't find any bottleneck.

In general, efficiency has nothing to do with maximum hardware computation power. You can be efficient at any power level, solving a particular problem. The interviewee didn't mention anything about maximum efficiency at all. Are you reading from the full paper article by any chance ?

Maximum efficiency usually just means 100% efficient (or rather no inefficiency), whatever efficiency means. But that's not what the dude is saying.

They couldn't find any bottleneck probably means KZ4 hasn't pushed the system in any specific way yet.

 

Not sure if this the right thread or was this even posted already, but someone actually managed to do a C++ compatible D3D11/DXGI/D3DCompiler API on top of PS4's low-level graphics API (supposedly new version of libGCM)

http://n4g.com/news/1226625/paradox-and-yebis-running-on-ps4-with-direct3d11-layer

 

Where did that info come from? because to me it look like that website just took the Yebis video & changed the name to say it was running on the PS4.

Edit: I see it now.

http://paradox3d.net/blog/direct3d11-ps4.html

 

Too much memory is never a bottleneck. Too little memory is. Even X360 and PS3 likely could have taken full advantage of 8 GB of memory. Of course, loading up the data for 4-8 GB worth of game assets off of the storage subsystems each console had would be a rather significant bottleneck if you consider load time/streaming to be a bottleneck.

I think that hits right at what Cevat Yerli was implying when he said that this console generation would be giving PC-centric developers a leg up on exploiting the power in the consoles versus console-centric developers due to how developing a title on the next gen consoles will be more like PC game development than traditional console development where you are spending significant time wrangling with the hardware itself.

Also fits in with how quite a few developers have stated they are switching their primary development platform to PC as moving from PC to console is much easier.

Regards,
SB

 

Technically he's incorrect, but he gets the idea across.

Bottlenecks are relative. It is where the system has the least throughput and the whole system's performance depends on the bottleneck. Of course, usage patterns may change this bottleneck.
But nevertheless, in any system there will always be a bottleneck. Unless you have many things that run at similar throughput and you'll end up with a system with many bottlenecks or the whole system itself is a bottleneck.

However, whether it matters or not is a whole other story. Currently it seems that the PS4 is well designed enough that there is no clear culprit component holding down other components and that this culprit may change hands when doing mildly different stuff. In general such balanced designs.

 

...and it doesn't seem to restrict the developers to a particular implementation approach/model.

 

He mentioned system memory being "ring-fenced". I'm interested in this, what does it mean?

http://www.videogamer.com/news/ps4s...om_third-party_devs_until_console_reveal.html

 

Basically there is enough reserved memory for the OS that it can remained loaded while you are playing a game, rather than having a minimal version while the game is loaded.

 

?

http://www.vgleaks.com/orbis-gpu-compute-queues-and-pipelines/