PhysX: PS3 can handle it; 360 features limited

[BlueTsunami]

You have to have PhysX PPU hardware to get 40 fps.

Yep....which is kinda crazy because you got the PhysX hardware going and 25% of the CPU (one of the cores on a dual-core) is being taken up. What physics demonstrations did they do?....well...its already been stated..but I would love to see a video or something...or are these just test numbers?

 

[pc999]

Thanks guys for explain the whys. So can someone explain the "What this can add to PCs with the Physics card and PS3, that the other choices can't." What differences will this give games made only on the PS3 that can't be produce else where?

Every things that is on water, eg ships battles in multiple cenarios from calm to tempests, here explosions affect water thus affect the ship, or a platform game which is on liquid surfaces with multiple variables, to sum any kind of cenario here liquids affect your performance.

 

[Alpha_Spartan]

I can imagine the sychophants blowing this way out of proportion. "OMG!! Xbox 360 is teh too weak to run PhysX!" All this states is that the Novonyx SDK in its current form is better suited for the PS3's architechture and PhysX processors.

 

[one]

Thanks
Do they have any numbers for PS3/XB?

The 4gamer.net article reports

Mr. Lassanske defined the resource that can be used for physics calculation in a single-core PC as 10% to 15%, and pointed out that it's just for physics for enemy characters, vehicles, and items, at best. However, in a dual-core PC, the first core can use 30% at the max for physics and the second one can use 100%, so physics caclulation of hundreds of objects, tracking (judging whether an object requires physics calculation) of thousands of objects are possible, and particle/grass physics effects become available too. Fluid simulation like streaming water is possible with some limits. Though logical CPUs in Xbox 360 are 6, they don't push up the physics perf very much as it requires processing OS and DirectX.
Besides, he said, in PS3, physics calculation of thousands of objects, tracking of tens of thousands of objects, and limitless effect physics and fluid simulation are possible.

 

[pso]

Corrected.

It basically matches what Ageia stated at CEDEC 2005 in this week in Japan.

http://www.4gamer.net/news.php?url=/news/history/2005.08/20050830235053detail.html (article in 4gamer.net (Japanese))

They basically said

PC with PhysX hardware = PS3 > Xbox 360 > dual-core PC > single-core PC

since more cores can be dedicated to physics calculation in PS3 while Xbox 360 CPU cores have to manage OS/libraries. Novodex Rocket 2.0.001 was used as a demo, and Pentium XE 3.2Ghz dual-core CPU could run it at 5-7fps while the same PC with a PhysX card could run it at 35-40fps. Apparently PhysX card will be available in December for $250-$300.

What if the the 360 doesn't have to share its cores with other libraries? The translation is "probably", that's not good enough. Either Ageia knows for a fact and explicitly states this or it will just create confusion.

 

[pipo]

Yeah, but you probably want the Cell's to do some other stuff too right?

What if we throw some AI in the mix for example?

 

[Titanio]

The 4gamer.net article reports

Cheers, sounds good for PS3.

BTW, Havok I think has a presentation at Eurographics this week which could be interesting. There are actually a couple of presentations there, one on Cell also, one on the X360 GPU and a roundtable with IBM, NVidia and ATi on next-gen consoles. It's actually local to me but I can't attend I'm afraid.

 

[Titanio]

What if the the 360 doesn't have to share its cores with other libraries? The translation is "probably", that's not good enough. Either Ageia knows for a fact and explicitly states this or it will just create confusion.

I think they're comparing under equivalent conditions. I doubt they'd factor in something on one platform and not on another. The other quote specifically singles out the OS/DX btw.

I think it's as much an issue of the plurality of processors on Cell vs X360 though. I mean both have other things they need to be doing (as pipo asks about AI, as you ask about libraries etc.). But Cell physically has more to divvy up, and for this particular task - physics - it would seem well suited.

 

[Shifty Geezer]

Logical cores on XB360 = 6?? There's three cores, and the other threads are there to optimize the processor with other work while the first thread is waiting on something. It's not 6 cores.

The explanation sounds fair. If working with datasets that fit into a SPU's LS then Cell's BW advantage there is obvious, keeping the FPU's fed. A later version of the Novodex engine might manage XB360's cache on a lower level to keep prefetch the data and keep it more local, maybe. Don't know how much they've investigated this. If it is an architectural limit, it'll be the way XeCPU and Intel CPU's work in main RAM primarily, while SPU's work in local store. And credit to STI, that's why they designed Cell on that principle. If it doesn't have an advantage in some areas they just wasted their time and money!

 

[Alpha_Spartan]

Logical cores on XB360 = 6?? There's three cores, and the other threads are there to optimize the processor with other work while the first thread is waiting on something. It's not 6 cores.

1 thread equals 1 logical core. Each core can be seen as two logical cores. Don't make this more difficult than it needs to be.

 

[one]

What if the the 360 doesn't have to share its cores with other libraries? The translation is "probably", that's not good enough. Either Ageia knows for a fact and explicitly states this or it will just create confusion.

AGEIA is one of the closest XNA partners and lends its hands with Microsoft for the integration of NovodeX for Xbox 360 multicore CPU, so I presume they have good knowledge of the actual Xbox 360

 

[Guden Oden]

Isnt this kinda premature. Saying the Xbox 360 cant handle Fluid physics so soon?

It can of course handle any kind of physics, provided it has the memory capacity to hold program code and the simulated environment. Of course, it might not run particulary fast, which is likely the issue here; something with the xCPU is holding back fluid simulation performance too much - cache thrashing perhaps - and apparantly it can't be run at playable framerates at the moment. This may well change though - after all, we know program code can be greatly optimized over time.

It would seem though that Cell is inherently more suited to these tasks, at least from what Aegia is alledging. Others may disagree, who knows?

 

[V3]

They can just get Xenos to do some work I suppose, if it need be, or they can lessen the iterations. Its a freaking game afterall, accurate result doesn't matter at all.

 

[Shifty Geezer]

1 thread equals 1 logical core. Each core can be seen as two logical cores. Don't make this more difficult than it needs to be.

Yes, but in reference to the articles presentation of the idea 'more cores = better' (it was talking about single and dual core processors) logical cores don't count for much. If Novodex were to take up 100% of a single threaded XeCPU core, making that core dual-threaded won't reduce the Physics to consuming 50%. I'm not sure the article writer appreciates that. At least as the article was worded it sounded like he was saying XB360 has 6 cores to work with and could dedicate one or three to Aegia, but these cores were being gobbled up by OS stuff which I don't think is the architectural reason.

 

[pso]

AGEIA is one of the closest XNA partners and lends its hands with Microsoft for the integration of NovodeX for Xbox 360 multicore CPU, so I presume they have good knowledge of the actual Xbox 360

True but they should have used a better and more precise word than 'probably' to get to the point.

 

[Alpha_Spartan]

So the PS3 can run a particular physics SDK better than the Xbox 360. So what?

 

[Shifty Geezer]

So hooray for PS3! I think the important point (least for me) is that PS3 is capable of running high fidelity physics akin to a $250 card for a PC (plus a dual-CPU PC at that). That's a nice thumbs up for the design of Cell and certainly a worthwhile point on a technical forum that wants to consider the pro's and con's of the different approaches to console hardware.

 

[Jawed]

Shifty, a P4 is two cores logically, even though it is a single core physically - hyperthreading. Sure it isn't a 100% speed-up from the second core (15% is the figure often seen, under ideal conditions, e.g. encoding media).

Here you can see the performance gain from hyperthreading in P4:

http://www.techreport.com/reviews/2002q4/pentium4-3.06/index.x?pg=7

Here is an explanation of the various terms related to concurrently executing instructions:

http://arstechnica.com/articles/paedia/cpu/hyperthreading.ars/1

This article describes Xenon in some detail:

http://arstechnica.com/articles/paedia/cpu/xbox360-2.ars

Jawed

 

[mckmas8808]

So the PS3 can run a particular physics SDK better than the Xbox 360. So what?

Well it does kinda matters. Games like Splinter Cell: CT had some advantages on the Xbox over the PS2. The biggest one to me being the graphics. The lighting in the Xbox version was WAAAY better than on the PS2. Its the small stuff like that, that can change a game IMHO.

 

[pjbliverpool]

So hooray for PS3! I think the important point (least for me) is that PS3 is capable of running high fidelity physics akin to a $250 card for a PC (plus a dual-CPU PC at that). That's a nice thumbs up for the design of Cell and certainly a worthwhile point on a technical forum that wants to consider the pro's and con's of the different approaches to console hardware.

I don't think its been said anywhere that you need a PPU plus dual core CPU to match cells abilities. All thats been said is that it takes a PPU enabled PC or cell to support all of the Novadex features. I don't think thats dependant on dual core and I don't think its saying that they support those features to the same degree.

They may both support the same features while the PPU can handle them twice as fast when coupled with a modest single core CPU.