Next-gen console operating systems - resources reserved?

[Shifty Geezer]

I don't know that Sony spoke of doing all these differnt functions concurrently while playing games though. To take up 32 GFLOPS of maths processing to enable online chat and stuff? That's a huge waste. If XB360 can manage it's rather extensive OS functions in 5% of two cores, why take up a whole core of Cell in PS3? Surely it'd be better to use <10% of the PPU which would be better suited to OS work I imagine.

Besides, what actual activities are you expecting to run while gaming? A lot fo that PS3 functionality doesn't sound like something you'd run concurrently. Like I say, is it not far more reasonable to expect a PSP like Crossbar interface on startup where you choose what you want to do?

 

[Titanio]

I don't know that Sony spoke of doing all these differnt functions concurrently while playing games though. To take up 32 GFLOPS of maths processing to enable online chat and stuff? That's a huge waste. If XB360 can manage it's rather extensive OS functions in 5% of two cores, why take up a whole core of Cell in PS3? Surely it'd be better to use <10% of the PPU which would be better suited to OS work I imagine.

Besides, what actual activities are you expecting to run while gaming? A lot fo that PS3 functionality doesn't sound like something you'd run concurrently. Like I say, is it not far more reasonable to expect a PSP like Crossbar interface on startup where you choose what you want to do?

They were quite explicit about this functionality being available concurrently with games.

The impression I got was, you may not be the only person ever using a PS3 at one time. While you are playing a game, there may be someone watching another screen (with dual video out) doing something else, or someone remotely accessing your PS3 from their PSP, or what have you. Perhaps there could be "windowing" features to let people do different things on two different parts of one TV screen also (they didn't hint at this at all, it's just a thought). But of course, you yourself may also be calling up other things during games, like video chat and music etc.

Here are some quotes from E3:

Kutaragi:

"Finally, in addition to games, PS3 will of course be able to perform non-gaming functions such as Digital Audio, Digital Music, Movies, and photographs, even during gameplay. Video communication over the network or internet browsing can also be enjoyed simultaneously while playing games."

Masa Chatani:

On the dual video out - the slide here has "multiple applications" across two screens as one bullet point:

"This amazing innovation [dual video out] will allow users to enjoy the multiple channels of entertainment and information at the same time from multiple sources. If you are fortunate enough to have two HD monitors, then you can enjoy a panaromic view which enjoys a horizontally seamless image of 32:9 aspect ratio. An even more .. use of the PS3 dual screen will be to show tactical and statistical information to be displayed even on the PC monitor while playing the sports game on larger main screen. Likewise, you can be in video chat with your friends at the same time as playing game. This is not simply two displays of the same game but allowing the user to control multiple sources of entertainment simultaneously, further fusing the real and virtual worlds together. "

On wifi/networking:

"This allows the PSP to become a remote controller, as well as remote screen. whether you are in the next room or the other side of the world. From any remote location, PSP can access PS3 to play the role playing game which runs on your PS3 at home. The always-on, always connected nature of PS3 means that your secure media can be accessed remotely at any time over broadband or wireless networks."

"PS3 is an always on, always connected device. The four Cs of the network, Commerce, Community, Content and Communication are built-in to every aspect of the system design, and operating system, allowing applications to easily exploit these features. Media browsing and network interface are built-in to the operating system and allow the user to handle multiple tasks simultaneously, even while playing a game. Video calls can be made and received, music and streaming media browsed, new content for games purchased and downloaded."

I don't know if this requires an entire SPE to itself, but I wouldn't be surprised. And you know, the OS may also provide APIs for games to integrate some of these services more directly. They could perhaps also stick a couple of other relatively lightweight services on a reserved SPE too, like maybe audio.

And I may be reading too much into it, but on the block diagrams shown at E3 of PS3 system architecture, the last two SPUs on Cell (of eight) are faded out for no apparent reason - 6 are shown "fully"..

 

[Shifty Geezer]

Kutaragi:

"Finally, in addition to games, PS3 will of course be able to perform non-gaming functions such as Digital Audio, Digital Music, Movies, and photographs, even during gameplay. Video communication over the network or internet browsing can also be enjoyed simultaneously while playing games."

Okay, that's pretty clear. One I hadn't picked up on. I'd still ahve thought this would scale on use though. Like your PC doesn't reserve resources for multitasking and leave bits sitting idle in case you'd multitask, I's expect PS3 will have everything available but of you start multitasking, resources will be given over to the other functions. Certainly I'd rather have a 5% drop in game performance when someone's streaming a video which happens all of 1% of the time you play, then have the performance capped at 85% waiting for someone to multitask!

 

[ERP]

Okay, that's pretty clear. One I hadn't picked up on. I'd still ahve thought this would scale on use though. Like your PC doesn't reserve resources for multitasking and leave bits sitting idle in case you'd multitask, I's expect PS3 will have everything available but of you start multitasking, resources will be given over to the other functions. Certainly I'd rather have a 5% drop in game performance when someone's streaming a video which happens all of 1% of the time you play, then have the performance capped at 85% waiting for someone to multitask!

The difference is your PC has paged virtual memory, and you deal with applications going into slow motion occasionally when it pages. Your PS3 won't, Sony will have to reserve any spae they might use while the game is running.

I have heard rumours but I have no confirmation of the final amount.

 

[Titanio]

I would think in a realtime environment, it'd be important to know what was always going to be available to you. A game could be pushing the hardware really hard, and then someone comes along and starts video chat, what happens to your game's performance? I think it's better to have X amount of performance guaranteed at all times.

That said, this is a similar problem on X360 and they seem to have gone for the "sometimes it'll take X%, sometimes Y%" approach.

Is it OK to say you'll have a certain amount available at all times, and then sometimes you'll have a little more, sometimes not, but don't rely on it? How about providing some "light" game resources through a reserved SPU like audio perhaps also? If they could offer something like that to a game at all times regardless of what else was being done, it'd make sense to do so too (take whatever little burden away from the other SPUs).

 

[Shifty Geezer]

If you expect people to be using Video chat often, reserving the resources makes sense. If people are going to use video chat rarely, reserving it doesn't make sense. It depends how much Sony anticpate PS3 being central to household activities and how much use it'll get for non gaming function. But if it doesn't ship with an HDD, chances of it being used for non-gaming functions seems pretty remote. And if it does become the one-box solution to every household's entertainment needs, that's suicidal regards Sony's CE division! They're still going to want to sell digital recording boxes and stuff I'd have thought.

I personally don't see anything wrong with taking a hit in game performance when multitasking. If I run a video on PC while playing a game, I expect the game to not run as well as I haven't as much to throw at it. I'd be right disappointed if when I wasn't running a video my PC game still ran as though it were, because there were resources available that it wasn't using. Of course in a closed box with the lower spec I'd never notice except learning this was the case!

 

[Ragemare]

I haven't read everything, but I don't think this is true? Well the devs who were running their games thusfar on the PPE only would be pulling off some sort of miracle if it were true

And yes, in my original post, I was talking about the possibility of one of the 7 SPUs being reserved, leaving 6 for game code. I think that'd be acceptable.

I think the the second half of my post was more accurate. It seems the PPC's main purpose is too carry out OS and utility functionality so the application processes have the SPU's to themselves.

If most of the game code can be ran on the SPU's, then the PPC can be left to deal with drivers, resource management etc. You don't need to reserve an SPU for system level stuff, I don't think it would make sense to use an SPU for OS stuff anyway because you would have to rewrite more of the OS code (presumeing they are using one that already exists) and I'm not sure it makes sense from a architectural point of view.

They might reserve an SPU to do something, but I doubt it will be system level stuff.

 

[Fafalada]

I don't know if this requires an entire SPE to itself, but I wouldn't be surprised. And you know, the OS may also provide APIs for games to integrate some of these services more directly. They could perhaps also stick a couple of other relatively lightweight services on a reserved SPE too, like maybe audio.

Rationalizing aside - if they are reserving SPEs, the main reason for it is DRM.
Everything else, from their PR to things you mention like potential game-code services, is just fluff that may or may not come with it.

Of course in a closed box with the lower spec I'd never notice except learning this was the case!

Well some closed boxes will have to compete with other products - unlike ahem PSP, where the thing could ship with 8MB usable memory and it still wouldn't have any real competition.

 

[Titanio]

You don't need to reserve an SPU for system level stuff, I don't think it would make sense to use an SPU for OS stuff anyway because you would have to rewrite more of the OS code (presumeing they are using one that already exists) and I'm not sure it makes sense from a architectural point of view.

They might reserve an SPU to do something, but I doubt it will be system level stuff.

True, the OS will be resident on the PPE only, but I suppose I'm just looking at all these potential apps as an extension to the OS, built-in, and those apps could indeed use a SPU.

DRM & security are undoubtedly Sony's prime motivators if they do do this, but at least there'd be some tangental benefit for non-game apps too. I guess your view on this may depend on how useful you'd find the stuff they're talking about.