SPU usage in games

[Carl B]

Ok, bunch of posts deleted for being off topic. Let's drop the console <---> PC comparisons and get back to the heart of the thread. As far as the GPU/CPU thing goes, I think putting the rest aside, we all recognize what Joker454 was saying when he was trying to highlight modern games often being GPU limited.

So... SPU usage in games; that's the topic!

 

[Obakan]

Is it true that the sound in PS3 games takes One SPU?
Just asking because I´ve heard a lot of this stuff on other forums.

 

[Carl B]

Is it true that the sound in PS3 games takes One SPU?
Just asking because I´ve heard a lot of this stuff on other forums.

It's true that if you're running sound on the SPU's, you must be running it on at least one. I think that's pretty obvious - what's your question exactly?

 

[Obakan]

It's true that if you're running sound on the SPU's, you must be running it on at least one. I think that's pretty obvious - what's your question exactly?

Sorry I didnt ask right, if you run the sound on the CPU, (Ps3 doesnt have a soundcard right?) does the sound need the power of a whole SPU?

 

[patsu]

Depends on what the game/developers need... it can take a fraction of a SPU, or even multiple SPUs.

 

[Obakan]

Depends on what the game/developers need... it can take a fraction of a SPU, or even multiple SPUs.

So it depends on how advanced (sound effects etc.) sound the developers wants in the game?

 

[Carl B]

Sorry I didnt ask right, if you run the sound on the CPU, (Ps3 doesnt have a soundcard right?) does the sound need the power of a whole SPU?

For the record I knew that's what you were asking Obakan, just wanted you to phrase it in a less innocent way.

No - of course it doesn't require the entire SPU. That said, even running "sound" itself can mean a lot of different things depending on what is going on aurally. Now just because the processing demands aren't for an entire SPU, doesn't mean some devs haven't sort of been cordoning one off for said operations for the sake of simplicity. Granted, I'm sure it varies. Since the Ninja Theory guys originally said they were taking such an approach - though I forget whether it was absolutely or for ease of breakdown that they said it - maybe one of them will chime in with the present state of audio on PS3.

 

[pipo]

So it depends on how advanced (sound effects etc.) sound the developers wants in the game?

Sure. But I'd guess most devs would rather use the power for other stuff.

 

[patsu]

So it depends on how advanced (sound effects etc.) sound the developers wants in the game?

Not just games... AV needs too. Search the forum for an interview with 2 Sony engineers who worked on SACD decoding.

I doubt the usual game audio effects will take up 1 full SPU. According to the developers, an SPU can outrun a PPU.

In addition, some games spread the work load dynamically among a group of SPUs, so they should be able to cut through the job queue, including audio jobs, pretty quickly.

 

[Carl B]

Does anyone know where that thread discussing the PS3 SDK audio additions went to? That would be the perfect reference point here, but I can't find it.

 

[patsu]

Is there one ? I must have missed it

 

[Gradthrawn]

No - of course it doesn't require the entire SPU. That said, even running "sound" itself can mean a lot of different things depending on what is going on aurally. Now just because the processing demands aren't for an entire SPU, doesn't mean some devs haven't sort of been cordoning one off for said operations for the sake of simplicity. Granted, I'm sure it varies. Since the Ninja Theory guys originally said they were taking such an approach - though I forget whether it was absolutely or for ease of breakdown that they said it - maybe one of them will chime in with the present state of audio on PS3.

Kojima's team seems to be pretty psyched about the use of audio with the SPUs. MGS4's development will be a good one to follow in that regard. There was a brief feature about on Gamespot but it was far more fluff than anything else.

 

[Arwin]

I missed it too.

I do want to point out that real-time surround mixing up to now has always been considered a rather hefty task, and I think Lair (and a few other games) supports 7.1 surround. Now for doing real-time surround stuff, you need to track the location of the sound origin in 3D space and mix all sorts of samples (from say all the different dragons, fireballs, and anything else that makes sounds) into a 7.1 surround sound uncompressed audiostream. While I'm sure that one day this may be reduced to a fraction of an SPU, I imagine it would be easy for the amount of data involved as well as the number crunching involved to take up enough for a development team to dedicate an SPU to it.

Of course, I really don't know anything about this, so I'm also hoping someone with actual experience on this subject chimes in.

 

[Carl B]

Well, I found the presentation I was thinking of:

https://www.cmpevents.com/GD07/a.asp?option=C&V=11&SessID=4226

...but I still can't find the discussion/slides that were around here. Maybe it was on some other forum? But that doesn't sound right...

Anyway - this is the thing we need the details on: MultiStream

Going back to my own interview with Scott Kirkland, he mentions that that's what they're using for audio themselves, and I imagine the majority of 1st/2nd parties (if not everyone) are doing likewise.

PS - Looks like there was also a presentation concerning MultiStream at Devstation 07, so what I remember could have been from either one.

 

[archangelmorph]

Well, I found the presentation I was thinking of:

https://www.cmpevents.com/GD07/a.asp?option=C&V=11&SessID=4226

...but I still can't find the discussion/slides that were around here. Maybe it was on some other forum? But that doesn't sound right...

Anyway - this is the thing we need the details on: MultiStream

Going back to my own interview with Scott Kirkland, he mentions that that's what they're using for audio themselves, and I imagine the majority of 1st/2nd parties (if not everyone) are doing likewise.

PS - Looks like there was also a presentation concerning MultiStream at Devstation 07, so what I remember could have been from either one.

There sure was.. as a matter of fact I have the presentation info on my Pc but i'm not sure if/what i'm allowed to divulge?

 

[patsu]

archangelmorph, I believe that presentation file belongs to me. Now can you return it to me pronto please ?

 

[archangelmorph]

I really don't want to get into trouble so if any other devs can give me a shout and let me know whether it's ok to describe the audio stuff from the Devstation presentation (slides + mp3) then i'll see what I can do..

 

[DeanA]

I really don't want to get into trouble so if any other devs can give me a shout and let me know whether it's ok to describe the audio stuff from the Devstation presentation (slides + mp3) then i'll see what I can do..

If you were at DevStation, you (or your company) are likely subject to the NDAs in force for Playstation developers, which would cover the subjects and materials disclosed at DevStation (as well as any materials available on PS3 DevNet).

Or that would be my (non-Sony-hat-wearing.. see my signature) take on it.. your mileage may vary. I am not a lawyer. Warranty void where prohibited by law etc etc..

Cheers,
Dean

 

[Jov]

Does anyone know where that thread discussing the PS3 SDK audio additions went to? That would be the perfect reference point here, but I can't find it.

Wasn't that the MSG4 thread and the reason for BR due uncompressed 7.1??

 

[Carl B]

Wasn't that the MSG4 thread and the reason for BR due uncompressed 7.1??

No idea... but I don't think so. Do you have a link to where that presentation would have been in the thread? The threads in the gaming section are dark waters to me.