Xbox 360 Vs. PS3: Graphics RAM battle?

[prankstare]

Originally Posted by jlippo

Yes, what it does is sample textures multiple times to get better quality.

Basically it samples the trapezoidal area on texture/polygon covered by the pixel.
More samples on that area/mipmaps better the quality and this is why there is different levels on AF.

Using AF does not use more memory as mipmap pyramid already has 'bloated' textures by 0.33 already when using mipmapping/trilinear filtering.
This thread is goldmine for information about anisotropic filtering.

I would also suggest on going to the source, when wanting to learn about consoles and reasons why developers do things like they do.
http://microsoftgamefest.com/2006.htm (note. clicking links downloads ALL presentations of graphics, audio... and so on.)
http://microsoftgamefest.com/presentations/2007.htm (just normal single presentation links.)
http://microsoftgamefest.com/presentations/2008.htm
http://microsoftgamefest.com/seattle2010.htm

For Cell on ps3, one only needs CellBE Handbook.

jlippo, thanks for the clarification. But how do you explain the fact Xbox 360 almost never uses any anisotropic filtering in their titles and PS3 does? If Xbox clearly has "better" graphics hardware, including the super-fast EDRAM, why would developers sacrifice AF on this console? For the sake of FPS? I don't think so. For the 4xAA + HDR? Maybe? I thought this was a matter of disc storage space (dvd9 vs. blu-ray), but you said AF has nothing to do with memory, so I am more and more confused.

Take this comparison video for instance: when you look at the ground, you see there are much more detailed graphics for the PC version of the game. Is that AF, tesselations or simply more graphics objects?

[jlippo]

Originally Posted by prankstare

jlippo, thanks for the clarification. But how do you explain the fact Xbox 360 almost never uses any anisotropic filtering in their titles and PS3 does? If Xbox clearly has "better" graphics hardware, including the super-fast EDRAM, why would developers sacrifice AF on this console? For the sake of FPS? I don't think so. For the 4xAA + HDR? Maybe? I thought this was a matter of disc storage space (dvd9 vs. blu-ray), but you said AF has nothing to do with memory, so I am more and more confused.

Performance is the only reason and no AF doesn't require any additional storage space when already using mipmaps. (Which you already use for performance, memory and quality reasons.)
Find the GPU related presentations from the Gamefest precentations and you will find following things.

Xenos has 32KB of texture cache and thus in recommended not to use trilinear with anisotropic filtering and if trilinear is used to use method which blends only very near mipmap is changed.
Simply put, when the cache is trashed the GPU stalls and you waste a lot of good rendering time.

Also all textures reside within main memory and use it's bandwidth, so textures do not use any storage or bandwidth from edram.
Daughter die doesn't have ALUs or TEX units, so the texturing or any alu related calculations cannot happen there, only write operations from ROPs. (only read operation is during for blendin transparent surfaces.)

Here's a couple of presentations which should get you started.
http://www.microsoft.com/downloads/d...displaylang=en
http://www.microsoft.com/downloads/e...displaylang=en
http://www.microsoft.com/downloads/e...displaylang=en

[prankstare]

Originally Posted by jlippo

Xenos has 32KB of texture cache and thus in recommended not to use trilinear with anisotropic filtering and if trilinear is used to use method which blends only very near mipmap is changed.
Simply put, when the cache is trashed the GPU stalls and you waste a lot of good rendering time.

Also all textures reside within main memory...

Oh, now I know why distant objects look so bad on the 360. You really solved the puzzle man! One of the little few things I have to complain about this console's graphics is exactly that and the little use of tesselations. Other than that, Xbox 360 could almost be compared side by side with PC platform IMO, but not bad for a 5 year-old hardware.

One more thing: do you think having unified memory architecture is really more efficient than the usual split pool memory found on the PS3?


PS: I will read and try to understand all those suggested links.

[m3dude]

Originally Posted by Viral

Memory doesn't mean much until you don't have enough of it. Since Xenos and RSX are quite close in capability the extra memory for Xenos is a big advantage and what I believe makes all the difference.

Don't even question it, 360 has the better balanced hardware design performance wise. PS3 only keeps up because of awesome developers.

"keep up" lol. when coded for exclusively ps3 is more capable than xbox

[XDanger]

Originally Posted by m3dude

"keep up" lol. when coded for exclusively ps3 is more capable than xbox

Yes ,PC and PS3 owners get a raw deal because the lame duck 360

Originally Posted by prankstare

Xbox 360 could almost be compared side by side with PC platform IMO, but not bad for a 5 year-old hardware.

With a pc also from 5 years ago yes.

[Ninja Prime]

Originally Posted by m3dude

"keep up" lol. when coded for exclusively ps3 is more capable than xbox

Not really, thats a fanboy line.

[jlippo]

Originally Posted by prankstare

Oh, now I know why distant objects look so bad on the 360. You really solved the puzzle man! One of the little few things I have to complain about this console's graphics is exactly that and the little use of tesselations. Other than that, Xbox 360 could almost be compared side by side with PC platform IMO, but not bad for a 5 year-old hardware.

One more thing: do you think having unified memory architecture is really more efficient than the usual split pool memory found on the PS3?.

In terms of just bandwidth unified memory is inferior, but as we know x360 has edram and that does help a lot.
In terms of flexibility unified is superior, although on case of x360 edram hinders this a quite a lot.

Biggest difference distant objects is how developers use their LoD and memory, so we cannot really say what machine is better in this case until we get definite answer from developers.

Tesselation is relatively new puzzle as it increases shading cost hugely due to the quad based shading cost and a basic cost of vertex transforming and calculating displacements.

[Viral]

Originally Posted by XDanger

Yes ,PC and PS3 owners get a raw deal because the lame duck 360

Are you even being serious? In what aspect does PS3 have a significant performance advantage over 360?

Originally Posted by m3dude

"keep up" lol. when coded for exclusively ps3 is more capable than xbox

Nope, as I said that's because of the developers. Once again, D-E-V-E-L-O-P-E-R-S.

[Ninja Prime]

Originally Posted by Viral

Nope, as I said that's because of the developers. Once again, D-E-V-E-L-O-P-E-R-S.

Developers...?

http://www.youtube.com/watch?v=KMU0tzLwhbE

[m3dude]

what xbox 360 game can stand up to the ps3 heavy hitters? or even come close? its pretty obvious the ps3 is more capable

[Viral]

Originally Posted by m3dude

what xbox 360 game can stand up to the ps3 heavy hitters? or even come close? its pretty obvious the ps3 is more capable

So you really don't think Gear of War 2 comes close to any PS3 game? You're delusional.

Even though I agree that PS3 has the better looking exclusives they don't even look better in every way. Most of it is just superior art direction.

[Viral]

Originally Posted by Ninja Prime

Developers...?

http://www.youtube.com/watch?v=KMU0tzLwhbE

lol