"Brenden D. Chase" <brenden.chaseREMOVE@THISgmail.com> ha scritto nel 
messaggio news:i1%we.38049$R21.5046@lakeread06...


>>> HAHA...  its been told that the AA will have to be programmed into a 
>>> core in the cell.  Unlike Microsoft who paid more for an actual chip 
>>> that does it.
>>
>> Cell can be post processing or vertex shading, AA is another thing, 
>> you're a bit confused
>
> so unconfuse me if you think i am.
>
> explain your answer

I'll try, but It's hard 'cause I don't write well in english, so I hope to 
be clear..

well, the spe in cell was originally thought very similar to "gpu pipeline", 
but sony found the performance very disappointing, so sony put a more 
hardware capable into ps3, the rsx

as all people knows, despite the fact that rsx will do majority of 3d 
operation, Cell and rsx could interact in some ways
the most accredited is that Cell can perform Vertex Process, 'cause rsx is 
able to fetch it with vertex data
another option is "post processing", so *after* that rsx finish to work on 
the frame buffer, rsx send the framebuffer to Cell's spe for further 
processing

(this is theory, I don't know if the bandwidth is adequate to perform this 
data exchange)

full screen anti aliasing fall in the middle of rendering,  deeply rooted in 
what rsx do, take an example for supersampling FSAA (this is the only AA 
feasible with HDR rendering turned on)

the scene is rendered at very high resolution (up to 4 times the original), 
then downsampled and scaled to output resolution, this can be done only by 
the hardware that do the rendering, in the original location of the frame 
buffer, and can't definitively done in a postprocessing time

however super sampling is very very bandwidth eater and the data easy fill 
the bus slowing down dramaticly the general performace by a 40-55% (the only 
direct-to-mem bus of rsx is a 700 Mhz 128 bit that is like a 350Mhz of a 256 
bit pc video card) if you think that p3 will use 1080p resolution

1080p is very heavy, it count a total of 2 milion of pixel, supersampling 
with this amount of pixel is a performance suicide
(an option can be turn off HDR and use the multisampling of rsx, with a 
performance hit of 30-40%, but the lack of HDR graphically is far beyond 
worse than a lack of AA)

for this reason can be arduous to see ps3 games with aa, at least in his 
firsts years of life, maybe later the devs will found some tricks to 
overcome the problem, who knows..

Xenos works very differently, AA is computed internally by a second core of 
the gpu that include both logic transistor

this core perform "on the fly" operations on the framebuffer (that is in the 
eDRAM) as like AA, stenciling, hdr and so on, without to touch and take up 
the GPU--MEM bus or the GPU--CPU bus, with a, well known, internal bus of 
256 GB/s

that's why framebuffer operations on x360 will came "for free" and this is 
the reason why microsoft pretend AA on every single title for his console

in reality this don't came magicly "for free" many believe because the 
second core make xenos a little more expensive, then a rsx solution
however to debate purpose, the performance hit of this solution is 1-5%

I hope that my crappy english is sufficient clear and I hope that is 
possibile a debate without insults