PS3 Backwards Compatability Revisited

[Carl B]

During his TGS keynote, Kutaragi mentioned that PS1 and PS2 titles would be able to be emulated 'over the network.' Now, this was based on the Eurogamer site translation/feed during the show, so first of all if there is clarification on this point, it is certainly welcome.

But what I am wondering is... what exactly did he mean by emulation? Is this indicative that Sony succeeded in the creation of an environment in which the EE+GS did not have to be included in the hardware? Is it a slower roll-out aiming to reach that eventuality?

Anyway I'm sure upon launch of the console, someone will bust open a PS3 and we'll know in short order what the extent of hardware provisions for B/C is; but the emulation 'over the network' caught my attention. PSP and PS3 emulating PS1 hardware I understand, but I'm just exploring the idea of whether PS2 emulation is really what was meant in that translation, or whether it's just straight PS2 ROM downloading, to be run on native hardware. The PS2 obviously has it's unique hardware traits that would make pure software emulation a seemingly difficult task (as oft discussed), but although Kutaragi has eluded to hardware considerations in the past, this speech may or may not be alluding to a different path taken/achieved at SCE.

Anyway, really I'm just wondering if anyone has a more complete understanding of that segment of the speech and Kutaragi's exact wording, since I can't really trust EuroGamer to have been on top of it to the extent I'd desire.

 

[Arwin]

I thought it was widely known by now that there seem to be two paths here:

1. as best a B/C as possible (i.e. games that won't work should be less than 5%) for your existing PS2 and PSX discs
2. a. downloadable PSX for PSP, which will have been modified to be both download efficient and capable of running decently on the PSP
2. b. a very similar option for PS3

 

[Carl B]

I thought it was widely known by now that there seem to be two paths here:

1. as best a B/C as possible (i.e. games that won't work should be less than 5%) for your existing PS2 and PSX discs
2. a. downloadable PSX for PSP, which will have been modified to be both download efficient and capable of running decently on the PSP
2. b. a very similar option for PS3

Right, and that definitely *is* known...

But before the consensus has been that at the minimum, there had to be a GS or GS-like chip inside PS3 dedicated to making consistent B/C a reality for PS2 games. I'm wondering if this segment of the speech now indicates a successful move to a 'truer' emulation environment.

 

[Shifty Geezer]

From those remarks, as mentioned in another thread, I understood that BC was out-of-the-box for disk based games, and PS3 would have available some titles for play over the network, a sort of 'play on demand' option. This is why the first titles are being kept to 'smaller titles' as the BW demands of larger titles exceed most people's internet connection speeds. Whether these games would be downloaded or streamed I can't guess.

I think the word 'emulation' isn't perhaps accurate, as it's all 'emulation' in a way (it's not a PS2, so it's pretending to be a PS2 one way or another). As per the last words on the matter, I expect there's some hardware thing in the PS3 to help.

 

[Carl B]

Yeah, that's what I was originally thinking; that 'emulation' had been used too loosely in the translation.

PSP and PS3 will be getting their PS1 virtual consoles of sorts, but I think for PS2, true emulation is still a ways away. BUT, it was - as it always is - of interest enough to push me to start a thread on B/C. If we crack open a PS3 and there's anything other than a full EE+GS in there, I imagine that it will make for some good discussions trying to address how they achieve system emulation.

 

[assen]

And if there IS a full EE+GS there, I wonder how they will render at 720p/1080p?

(my guess: initial batch of PS3s will have EE+GS and will output at 480i/p, with the PS3 part doing its best to upscale. Later on, they'll switch to emulation, and then we'll see true 720p rendering from select games.)

 

[kyleb]

And if there IS a full EE+GS there, I wonder how they will render at 720p/1080p?

I'm pretty sure they never said they would.

 

[ZiFF]

And if there IS a full EE+GS there, I wonder how they will render at 720p/1080p?

(my guess: initial batch of PS3s will have EE+GS and will output at 480i/p, with the PS3 part doing its best to upscale. Later on, they'll switch to emulation, and then we'll see true 720p rendering from select games.)

It isn't possible to truly render something that does not exist in 720p. Games will be just upscaled like on the 360.

 

[scooby_dooby]

I believe all KK said is that they would use a combination of software and hardware, whatever that means.

 

[mrdarko]

I believe all KK said is that they would use a combination of software and hardware, whatever that means.

Maybe.........ps1=Software and ps2=Hardware?

 

[Npl]

I believe all KK said is that they would use a combination of software and hardware, whatever that means.

I rather think that they start out with nearly 100% Hardware Emulation. Means that all games run on included PS2 Chips. Over time Sony will make more and more Games compatible with Software-Emulation, so in time of PSthree and PS4 the legacy PS2/PS1 chips can be dropped out entirely.

Just think of XBox360 BC and add an additional "safety layer".

 

[Danalys]

with the intimate knowlege of the original chips and the increase in speed and power of the PS3 they should be able to emulate it. they don't have rights problems like MS do. i thought the GS was basically a rasterizer to the Emotion Engine. the vector units can be done on SPEs. the in order/out of order execution difference might cause problems. really i don't know of anything that makes it impossible, but then i'm no expert, so there could be things that would be a problem i'm unaware of.

 

[kyleb]

It isn't possible to truly render something that does not exist in 720p. Games will be just upscaled like on the 360.

It is possible to render the games in whatever resolution you want; but, at least last I heard, BC games on the PS3 will simply be upscaled like BC games are on the 360.

 

[Carl B]

with the intimate knowlege of the original chips and the increase in speed and power of the PS3 they should be able to emulate it. they don't have rights problems like MS do. i thought the GS was basically a rasterizer to the Emotion Engine. the vector units can be done on SPEs. the in order/out of order execution difference might cause problems. really i don't know of anything that makes it impossible, but then i'm no expert, so there could be things that would be a problem i'm unaware of.

The problem is creating an emulated environment that can simulate the bandwidth of GS and it's eDRAM. In all past discussions on the topic, that has always been the main sticking point.

 

[Shifty Geezer]

The problem is creating an emulated environment that can simulate the bandwidth of GS and it's eDRAM. In all past discussions on the topic, that has always been the main sticking point.

Actually, that's been the most common concern from most people, but the PS2 devs here have said that's among the least of BCs concerns. There's lots of things GS does that standards GPU's don't do, and that's where things become awkward. Eithet RSX has hardware support for GS functions, or there's GS hardware in there to 'accommodate those games that do things in a way KK didn't expect them to do', or some magic syrup fresh from the Emulation Trees of Whizzywhizzy-Land

 

[SPM]

The problem is creating an emulated environment that can simulate the bandwidth of GS and it's eDRAM. In all past discussions on the topic, that has always been the main sticking point.

It would have been nice if 4MB eDRAM addressable by all the SPEs was built into Cell. I am sure programmers would have found a use for it, and not just for games.

 

[Danalys]

they've got the local store and you could probably just keep some stuff cycling around the ring bus untill needed.

 

[Shifty Geezer]

they've got the local store and you could probably just keep some stuff cycling around the ring bus untill needed.

I heard IBM were working on nanotechnology for the purpose of creating bicycles small enough for just that requirement...

How could you have stuff cycling around the ring bus? The bus moves data from one area to another. You can't have data sitting in it. You could keep moving data around from SPE to SPE, but it'd still occupy as much LS as the size of the data. You make it sound as though a couple of MBs could be left in the ring bus waiting to be fetched into LS for use

 

[Guden Oden]

you could probably just keep some stuff cycling around the ring bus untill needed.

Very bizarre statement... While there's sure to be buffer stages on the EIB, due to the fact it stretches almost from one end of the chip to the other, it'd only be to hold a data chunk for the single clock cycle it takes to move it from one section of the bus to the next. It wouldn't be a storage space, buses don't work that way.

 

[Danalys]

i was just thinking of something that might be doable. shouldn't have said probably.