Masayuki Chatani (SCEI CTO) interview

[DeanoC]

Deano - can I what you think about Cell as an assitant to the GPU for lighting? Generating more "dynamic" data for input to a GPU shader versus precomputed data used in some lighting algorithms, perhaps? Harrison seemed to allude to the possibility with reference to the DocOc demo, though my question isn't necessarily specifically in terms of the techniques used there (i doubt those techniques are generally useful).

Absolutely, long time ago I did a similar thing on MMX and a Voodoo (to do per-pixel lighting before the era of GPU dot products...)

Basically you would upload the normal map and parameter data/textures to an SPU, it scans across running the lighting equation. You might have to do it in tiles, so that everthing fits in an SPUs local mem but the FLOPs power of an SPU would churn through this pretty damn fast. Actually you might be able to have multiple SPUs work on different sections of the same texture.

The GPU would then just use the pre-lit textures (or apply a second set of GPU lighting). Of course this would be most usefull when GPU bound with spare SPU lieing idle...

The real advantage to this might be if the temporal frequency of the lighting change was quite low, then you could potentially reuse this pre-lit texture over several frames with the GPU adding in high frequency lighting (i.e. specular and reflections for example).

 

[Titanio]

Absolutely, long time ago I did a similar thing on MMX and a Voodoo (to do per-pixel lighting before the era of GPU dot products...)

Basically you would upload the normal map and parameter data/textures to an SPU, it scans across running the lighting equation. You might have to do it in tiles, so that everthing fits in an SPUs local mem but the FLOPs power of an SPU would churn through this pretty damn fast. Actually you might be able to have multiple SPUs work on different sections of the same texture.

The GPU would then just use the pre-lit textures (or apply a second set of GPU lighting). Of course this would be most usefull when GPU bound with spare SPU lieing idle...

The real advantage to this might be if the temporal frequency of the lighting change was quite low, then you could potentially reuse this pre-lit texture over several frames with the GPU adding in high frequency lighting (i.e. specular and reflections for example).

Cheers Deano. I figured it'd be useful to reuse the same calculations for a few frames, squeeze as much time for computation of each "update" as possible. BTW, Heavenly Sword looks fantastic I love the main character's style..

 

[pc999]

Now if we want to talk about procedural synthesis that creates procedural textures, than Cell is gonna whip XeCPU into touch in most cases...

This could mean that Cell will do the same in physics

Anyway it looks like they had offload some of this stuff to the GPU with their "fluid reality"...

 

[Megadrive1988]

Q. Gigabit Ethernet connectors are listed as In x 1 + Out x 2, what does it mean? Does it have router function and are they for WAN/LAN? Or do you use a special connection to connect multiple PS3s together?

A. It has no router function. It's supposed to be a switching hub internally, but I don't know about the meaning of In/Out frankly so will answer about it at the next opportunity. Of course you can connect PS3s together. After it's on sale, some will make a supercomputer by connecting many PS3s. Apparently Sony Picture Entertainment is considering to use PS3 in a rendering farm for movies.

Fap Fap Fap Fap Fap 8)

It was my dream to have some PS3s connected together to increase everything, and be able to play games that use this. even though this probably will not happen for consumers, I dont see why it wont happen for arcades, location based entertainment simulators, etc.

on another note, the full potential of the Cell architecture (not talking about PS3 specifically) probably wont be implemented until Playstation4, which bodes well for Cell's life.

 

[ecliptic]

Anyway the Cell and GPU work together is still limited by bandwidth. Declaring that the CPU can do something is all fine and dandy, but what the question is what will the hit on the bandwidth be?

 

[Titanio]

Anyway the Cell and GPU work together is still limited by bandwidth. Declaring that the CPU can do something is all fine and dandy, but what the question is what will the hit on the bandwidth be?

There'd be some, but you can bring your data into the SPE's local memory and work with the internal bandwidth as much as possible to minimise that. I would have thought the bigger issue would be the CPU/GPU interconnect, which seems to be nice and fat..

 

[Farid]

Q. Is it the same kind of approach in performance tuning?

A. Since we have performance analyzer tools for cache usage and bus usage that game developers have evaluated so far, we extend them further. We concentrate on tools to extract programmers power. Also, CELL has the function to emit processor usage statistics as a log. By using this, you can know detailed usage statistics of each core in CELL.

So, a PS3 PA is already available, to all developers?

BTW, great job one.

 

[mckmas8808]

Apparently Sony Picture Entertainment is considering to use PS3 in a rendering farm for movies.

I wonder if this is true. I don't see him lying. I remember Laa-Yosh saying something about rendering farms used to create Episode 3. Hey Laa-Yosh do you think this is possible? If so this could be a good reason to have alot of CELL based products interconnected in a home.
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HONDA CD100

 

[chachi]

Apparently Sony Picture Entertainment is considering to use PS3 in a rendering farm for movies.

I wonder if this is true. I don't see him lying.

Given that Sony and IBM have already discussed Cell-based workstations, and rack-mount systems, the idea of anybody, let alone a big company like that, trying to cobble together a PS3 based render farm is ridiculous. If it's not a PR gimmick then it's delusional.

 

[inefficient]

I believe in this case flexible will to slower not faster. Especially when performing the same services the SPE's excel at.

But then we don't know the details of the extent to which they actually implemented VMX in the 360's cores.

For really optimized number crunching work, I don't think its too outrageous to expect a single VMX unit to be slower than a single SPE.

 

[mckmas8808]

Hey chachi if I dont think its a PR gimmick. Even Ken K. said that a CELL based product could enhance the look of a DVD. Imagine what our current libary of DVDs would look like in 720p on the PS3. Ken talks about this hooking up of many CELL based products as if its one of his biggest achievments. I don't think its PR hype nor a gimmick.
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Ford fiesta

 

[jvd]

Hey chachi if I dont think its a PR gimmick. Even Ken K. said that a CELL based product could enhance the look of a DVD. Imagine what our current libary of DVDs would look like in 720p on the PS3. Ken talks about this hooking up of many CELL based products as if its one of his biggest achievments. I don't think its PR hype nor a gimmick.

how exactly will it make it look better ? Reencoding it on the fly to 720p ? that wont make it look better .

Don't get what he means by this

 

[PC-Engine]

Hey chachi if I dont think its a PR gimmick. Even Ken K. said that a CELL based product could enhance the look of a DVD. Imagine what our current libary of DVDs would look like in 720p on the PS3. Ken talks about this hooking up of many CELL based products as if its one of his biggest achievments. I don't think its PR hype nor a gimmick.

how exactly will it make it look better ? Reencoding it on the fly to 720p ? that wont make it look better .

Don't get what he means by this

He probably means upconverting 480p to 1080i like those upconverting DVD players. Anyway Xbox 360 would be able to do this too not to mention that some upconverting DVD players actually make the resultant video quality even worst.

Sometimes is just better to let your tv do the upconverting.

 

[chachi]

Hey chachi if I dont think its a PR gimmick. Even Ken K. said that a CELL based product could enhance the look of a DVD.

It's a gimmick in the sense that suggesting anyone would build a render farm out of PS3 units is just stupid. Surely I don't have to point out the various reasons why kludging together a room full of consoles is a bad idea? This is the market where a Cell-based rack mount system would be useful, and it's not like they haven't already talked about doing just that. The quote as given seems a bit like the old "Saddam using PS2 systems to control his nukes" dodge to impress people with how powerful it is than anything anyone would actually do.

 

[Goragoth]

Ken talks about this hooking up of many CELL based products as if its one of his biggest achievments. I don't think its PR hype nor a gimmick.

The exact point I believe that chachi was trying to make is that while it makes lots of sense to link a bunch of cells together for various tasks (such as rendering CGI) it is idiotic to use PS3's for that purpose. Much of the hardware would be essentially useless (the RSX, most of the networking, BR drive, mem card readers, etc...) while other parts are underpowered (not enough RAM). I would imagine rackmount systems with two or more CELLs per box plus 2gig+ of RAM each custom built as distributed computing nodes would make much more sense and that's what would have been meant in the interview. Also I believe Sony made similar comments about the PS2 being used to render CGI, something that never happened (though I do believe that this time around CELL render nodes are a very real possibility and something I'm very excited about, this is a place where all those FLOPs really do mean something).

 

[BOOMEXPLODE]

A university once created a farm of 70 PS2s for research purposes. The project doesn't seem to be active anymore though. One does wonder if they could have just bought 70 EE processors from Sony instead of the entire system, although this would have required custom hardware and presumably would have made the experiment even more expensive.

 

[mckmas8808]

The exact point I believe that chachi was trying to make is that while it makes lots of sense to link a bunch of cells together for various tasks (such as rendering CGI) it is idiotic to use PS3's for that purpose. Much of the hardware would be essentially useless (the RSX, most of the networking, BR drive, mem card readers, etc...) while other parts are underpowered (not enough RAM

Yeah I know that make sense. If I were Sony I would EDIT:NOT want to use 20 PS3s to make a movie. Making they thought about it with lower budget movies coming out on Sony Pictures or Columbia. They may need to save a few million dollars or something. :?
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Toyota Hilux Surf Specifications

 

[jvd]

The exact point I believe that chachi was trying to make is that while it makes lots of sense to link a bunch of cells together for various tasks (such as rendering CGI) it is idiotic to use PS3's for that purpose. Much of the hardware would be essentially useless (the RSX, most of the networking, BR drive, mem card readers, etc...) while other parts are underpowered (not enough RAM

Yeah I know that make sense. If I were Sony I would want to use 20 PS3s to make a movie. Making they thought about it with lower budget movies coming out on Sony Pictures or Columbia. They may need to save a few million dollars or something. :?

IT would be dumb to use a ps3 .

They are much better off making server racks with 2 cells 1x8 each and give them huge amounts of ram with fat bandwidth and hardrive space for rendering . I don't see an rsx being usefull in off line rendering and instead of the cost of that chip they can most likely add in alot more ram which is important .

 

[X-AleX]

[quote="nelg"
Now if we want to talk about procedural synthesis that creates procedural textures, than Cell is gonna whip XeCPU into touch in most cases...

Sorry DeanoC, isn't XeCPU supposed to be "procedural synthesis-based"(forget about the spelling, I'm no expert), as
http://arstechnica.com/articles/paedia/cpu/xbox360-1.ars ArsTechnica noted?
Why did you say that Cell whipes XeCPU ?

 

[Shifty Geezer]

There is no 'procedural synthesis' based processor. Any processor can do it. XeCPU is designed to do it well, but those design features are shared by Cell which has more processing oomph and processors better suited to the task I believe.