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[Raistlin]

Very little info has been released regarding RSX, and NDA's have prevented devs from saying practically anything. I know based on transistor counts, and the fact that certain parts of the 7800 do not make sense in a console - people have been wondering where the extra transistors are going to. Some have wondered if it's for a PS2 chipset (or at least part), as that is how PS2 handled PS1 'emulation', and it is known the PS3 will play all previous playstation games.

What I'm wondering is what else such a chipset could be used for? In the case of PS2, the PS1 CPU also doubled as an I/O processor. With PS3, the power of a PS2 - plus the fact it may be imbedded in the RSX itself - makes me wonder just what other sorts of things it could be used for.

Since it is potentially imbedded in the RSX, is it not possible it could have direct access to RSX memory – and therefore, potentially the framebuffer? Since it would be in effect an independent processor, could it be used as a post-processor directly on the framebuffer with basically no impact on the rest of the system's processing power (minus the tiny bit of overhead to command it)?

If possible, wouldn’t this give developers access to all sorts of post-processing effects that are normally handled on ‘finished’ framebuffers? Basically stuff like filters – blurs, grains, haze, etc. - not to mention some type of AA?

Is this at all possible?

 

[Deg]

didnt read your paragraph but there no such thing as free AA.

 

[SolidSnakex]

didnt read your paragraph but there no such thing as free AA.

Yah, the 360 has done a good job of showcasing that. I remember XBox fans touting that as one of the big pluses the 360 had over the PS3, and as we've seen jaggies still exist on that system.

 

[jett]

Sure...as free as the "free" AA witnessed in 360 games.

 

[Mefisutoferesu]

Well, others have speculated the almost exact same thing you have... using the 4MB of sdram in the GS to do all sorts of effects, AA being the most... err, worried over, but as I recall it's continually shot down time after time. Whether it be because Kutaragi has commented he's against edram or techincal issues keeping it from happening and so forth. Personally, I'm for it, but I can see how it can cause a lot of issues particularly in terms of BC. Anyway, yeah, assuming RSX has access to it, a lot of effect and even the sought after "free AA". Realistically, I doubt it happen, nice to dream though.

I miss Version's "drive by"s.

 

[Sqrt_minus_one]

Well you would still impact the memory bandwith/fillrate no matter what form of AA you emplyed.

On a side note, pure video which everyone expects to be excluded: was it not said at CES that the RSX was processing video as well so perhaps pure video will stay afterall. Or are they doing the video processing in the fragment shaders of RSX.

 

[Raistlin]

didnt read your paragraph but there no such thing as free AA.

Read the post, and then you'll understand my question

 

[momolicious]

they could probably "imitate" free AA

 

[Raistlin]

Well, others have speculated the almost exact same thing you have... using the 4MB of sdram in the GS to do all sorts of effects, AA being the most... err, worried over, but as I recall it's continually shot down time after time. Whether it be because Kutaragi has commented he's against edram or techincal issues keeping it from happening and so forth. Personally, I'm for it, but I can see how it can cause a lot of issues particularly in terms of BC. Anyway, yeah, assuming RSX has access to it, a lot of effect and even the sought after "free AA". Realistically, I doubt it happen, nice to dream though.

Would it actually need edram though if the PS2 is embedded on RSX and actually has direct access to it's RAM?

Is regular RAM not fast enough to keep up with 60hz?

 

[Mefisutoferesu]

Well you would still impact the memory bandwith/fillrate no matter what form of AA you emplyed.

On a side note, pure video which everyone expects to be excluded: was it not said at CES that the RSX was processing video as well so perhaps pure video will stay afterall. Or are they doing the video processing in the fragment shaders of RSX.

Well, you need something to output the video feed, RSX would be in charge of that. I'd be pretty surprised to see purevideo in the RSX. It really does seem like a waste.

 

[gofreak]

What you're saying is if GS was embedded in RSX, why not use its edram?

Kutaragi has said that eDram doesn't make much sense for PS3, so I do not think you'd see such a usage. Also, it's not confirmed how PS2 backward compatability is being achieved.

 

[Nightbringer]

Playstation2 (and Gamecube) has the problem that you need to render the scene 2 times for FSAA and thanks to it the polygon performance is cut in half.

Playstation3 doesn´t have this problem, because it has "free" antialiasing or in other words, PS3 doesn´t need to render the scene extra times for FSAA.

 

[choplifter]

in an ideal world, PS3 games would all have 8x or 16x Anti-Aliasing
at some cost but not enough to turn it off.
As for PS2 games running on PS3: 32x AA

4x anti-aliasing for the next generation is extremely disappointing, even if it was free.
I feel that the PS2-GCN-Xbox generation should've had 4x AA.

 

[Raistlin]

What you're saying is if GS was embedded in RSX, why not use its edram?

Would that be the only way to do it? If it is - then could they do it?

Kutaragi has said that eDram doesn't make much sense for PS3, so I do not think you'd see such a usage. Also, it's not confirmed how PS2 backward compatability is being achieved.

Maybe Ken was referring to the PS3 having it's own dedicated edram? Maybe it doesn't make sense because PS2 will be there?

As far as how PS2 backward compatability is being achieved ... I understand that. What I'm asking is IF they are achieving it by this means, would post-processing be achievable.

 

[tahrikmili]

If only people could understand that AA did not mean total elimination of jaggies..

XBOX360 does have a certain amount of free AA, it just does not have enough to make them disappear.

 

[Raven.]

in an ideal world, PS3 games would all have 8x or 16x Anti-Aliasing
at some cost but not enough to turn it off.
As for PS2 games running on PS3: 32x AA

4x anti-aliasing for the next generation is extremely disappointing, even if it was free.
I feel that the PS2-GCN-Xbox generation should've had 4x AA.

Fight Night's IQ is superb, I can't see any problem with the iq on my tv, it's like perfect.

 

[gofreak]

Playstation2 (and Gamecube) has the problem that you need to render the scene 2 times for FSAA and thanks to it the polygon performance is cut in half.

Playstation3 doesn´t have this problem, because it has "free" antialiasing or in other words, PS3 doesn´t need to render the scene extra times for FSAA.

That doesn't mean it's free. Bandwidth is the main cost here.

Ironically, though, using eDram and tiling would actually force you to do some vertex processing twice (not the whole scene, but for those polys that intersect triangle edges).

Maybe Ken was referring to the PS3 having it's own dedicated edram? Maybe it doesn't make sense because PS2 will be there?

Nah, he said he didn't make sense because you wouldn't be able to fit a 1080p buffer in a reasonable amount of eDram. PS2's eDram is only 4MB, much lower than what they might have otherwise put in PS3.

 

[HomerSimpson-Man]

in an ideal world, PS3 games would all have 8x or 16x Anti-Aliasing
at some cost but not enough to turn it off.
As for PS2 games running on PS3: 32x AA

4x anti-aliasing for the next generation is extremely disappointing, even if it was free.
I feel that the PS2-GCN-Xbox generation should've had 4x AA.

You're sure living in a dream world where there is 4x AA for decent performance in 1999-2000. Ideal indeed.

 

[Dr_Cogent]

Nothing in life is free, even AA. AA consumes bandwidth. Hence, it is not free.

 

[Deleted member 1159]

in an ideal world, PS3 games would all have 8x or 16x Anti-Aliasing
at some cost but not enough to turn it off.
As for PS2 games running on PS3: 32x AA

4x anti-aliasing for the next generation is extremely disappointing, even if it was free.
I feel that the PS2-GCN-Xbox generation should've had 4x AA.

Man, you're picky. 32x AA? Do you honestly think that would make any difference from 16x? 4x is more than adequate on PC for me...

 

[HomerSimpson-Man]

Man, you're picky. 32x AA? Do you honestly think that would make any difference from 16x? 4x is more than adequate on PC for me...

Anyone have pics of any game offering 32x AA?

 

[<nu>faust]

Xenos' the design is more one of finesse than brute strength, and the eDRAM allows for the implementation of several effects - at a minimal performance loss - that in a traditional environment would thouroughly tax bandwidth and performance.

If you don't see AA on all 360 games it's because ms has delivered the final kits 2 months before the launch and not all of the devlopers could optimize their code according to the strengths of the hardware, not because xenos can't.

 

[Raven.]

Anyone have pics of any game offering 32x AA?

Humus from Beyond3d, has a demo on his site where you can go up to like 64x AA(it's real friendly, and runs super even on mid-range pcs.)

 

[M3wThr33]

The very nature of AA means that it is impossible to have it for "free."

 

[choplifter]

STI-N (Sony Toshiba IBM and Nvidia) should increase the bandwidth of PS3's graphics subsystem so it can handle 8x AA efficiently, and even though it'll cost some, it could be optimised to have as small an impact on performance as possible.

256-bit bus and GDDR4 to the rescue ? I wish.

 

[Borys]

If it has to be calculated (computed) it's not free.

2x, 4x, 128x etc. - NOT free. There's no such thing as "free" in math (or programming).

 

[choplifter]

Xbox 360 ~ Xenos 4x anti-aliasing is payed for mainly by the transistors of the EDRAM unit; the EDRAM itself and the logic, and high internal bandwidth. plus a small percentage of performance/bandwidth cost. so of course it isnt free. it just doesnt hurt performance as much as AA on a conventional GPU / system.


am I right, or not ?

 

[iapetus]

TANSTAFAA.

Unless the console comes with vaseline to smear on your TV screen, that is...

 

[Raistlin]

Okay, I think I need to restate my point here. Many people have given one line responses stating 'nothing being free', etc. While this is in part my fault for not being explicit, I don’t think everyone is fully digesting my point.

While I understand any actual processing obviously isn't free (note the quotes around ‘free’), I meant it would have no major cost to the GPU since a separate processor would be doing the work in parallel. As brought up by several posters, bandwidth would be an issue, and I don’t see a way around that. I’m referring to the actual processing itself being ‘free,’ as far as the GPU is concerned, since ‘someone else’ is doing it.

Obviously one can always add extra dedicated HW for such a task, and ATI did exactly that for the 360. I’m just postulating that Sony has likely decided it ‘needs’ the PS2 (or at least part) inside PS3 for backwards compatibility – and wondering if that chipset could perform some double duty that would be beneficial for PS3.

 

[Fafalada]

wouldn’t this give developers access to all sorts of post-processing effects that are normally handled on ‘finished’ framebuffers? Basically stuff like filters – blurs, grains, haze, etc. - not to mention some type of AA?

AA is Not handled on finished framebuffers.
Anyway, GS has neither the internal-precision nor the data-format support to be usable in a modern chip in this fashion, the only way your idea could work would be if eDram was integrated into RSX processing flow itself.

On a side note, pure video which everyone expects to be excluded: was it not said at CES that the RSX was processing video as well so perhaps pure video will stay afterall.

Keeping purevideo active on RSX would be borderline retarded. The only purpose it would serve inside a PS3 is to make RSX yields worse - and it has no PR benefits whatsoever (obviously no practical usage benefits either, but those are of secondary importance anyhow).

 

[Panajev2001a]

AA is Not handled on finished framebuffers.
Anyway, GS has neither the internal-precision nor the data-format support to be usable in a modern chip in this fashion, the only way your idea could work would be if eDram was integrated into RSX processing flow itself.


Keeping purevideo active on RSX would be borderline retarded. The only purpose it would serve inside a PS3 is to make RSX yields worse - and it has no PR benefits whatsoever (obviously no practical usage benefits either, but those are of secondary importance anyhow).

I do not think it was using PureVideo, maybe a customized version for it... but really I think the RSX processing in that case was done using Shader programs.

 

[Ikaris]

NO SUCH THING AS FREE AA !

2X AA works by rendering the frame twice the size, then scaling it down.

Therefore, a frame buffer size of 720 would be rendered at 1440, then scaled down.

Both of these operations could never be considered "free".

4X AA, 4 times the size, and so on...

Ever see your game slow down by upping the resoltuion ? Same thing, but with a downsample thrown in... not trivial in terms of a performance hit.

 

[Panajev2001a]

NO SUCH THING AS FREE AA !

2X AA works by rendering the frame twice the size, then scaling it down.

Therefore, a frame buffer size of 720 would be rendered at 1440, then scaled down.

Both of these operations could never be considered "free".

4X AA, 4 times the size, and so on...

Ever see your game slow down by upping the resoltuion ? Same thing, but with a downsample thrown in... not trivial in terms of a performance hit.

Multi-Sampling AA or MSAA modifies things quite a bit: you use more memory (indicated by the AA factor basically), but you do not re-render the whole scene 4 times or at 4x the resolution: that would be more like Super-Sampling AA or SSAA.

MSAA uses one color for each of the samples needed to calculate the final color of the current pixel: the hit for both methods is the same in regards to fill-rate (you need to beable to write more pixels to the back-buffer during the same time slice and that implies also the ability of your connection to the on-chip/off-chip frame-buffer to sustain all the memory transactions this will produce without causing noticeable contention with the other operations the GPU needs to access its memory for).

There is a reason why AA has a bigger hit on say an old GeForce 3 card compared to say Xbox 360 .

Still you are trading off something even in the supposed "FSAA-For-FREE" GPU's. The amount of logic in the ROP's (Render OutPut unit) used to achieve higher fill-rate and the use of E-DRAM means added costs and potentially much lower yields, more power consumption, maybe the need of a multi-chip solution, etc...

 

[Ikaris]

Multi-Sampling AA or MSAA modifies things quite a bit: you use more memory (indicated by the AA factor basically), but you do not re-render the whole scene 4 times or at 4x the resolution: that would be more like Super-Sampling AA or SSAA.

Sorry, I should have mentioned I was referring to Super Sampling... you're right.