Vastaus: lcd televisiot uudelle boxille?
Kirvasto sanoi:
ulkaisupelien kohdalla tilanne voi olla niin että pelit näyttävät vähemmän sahalaitaisilta tavallisella televisiolla, koska alhaisemmalla resoluutiolla videomuisti riittää myös parempaan antialiasointiin. XO:n 10MB videomuisti ei riitä 720p + 4xFSAA:lla joten se vaatii hieman muutoksia pelimoottorin joita kaikki (yksikään?) pelivalmistaja ei osannut ottaa huomioon julkaisupelien kehityksessä.
XO:n GPU ei antialiasoi perinteisellä skaalausmenetelmällä, siksi näyttömuistia ei tarvita samalla
mitalla kuin perinteisissä kiihdyttimissä. Normaalistihan antialiasointi tehdään siten että
taustabufferi (jonne kaikki grafiikka renderöidään ennen kuin se näytetään) on neljä kertaa
suurempi kuin lopullinen resoluutio (4xFSAA), ja taustabufferin kuva resamplataan näyttöbufferiin.
(=pehmennetyt reunat)
XO hyödyntää optimoitua tile-pohjaista taustabufferia, jossa vain osa kuvasta renderöidään kerrallaan.
Lainausta
täältä:
...at HDTV resolutions nothing can fit into the 10MB of eDRAM with any mode FSAA enabled.
Xenos was specifically designed to perform very well in these cases by dividing the screen into
multiple portions that fit within the eDRAM render buffer space. This is similar to prior tile-based
renderers, but with a much larger base tile and with additional functionality to optimize the tiling
approach.
Lisää infoa
täältä:
The Xbox 360 Smart 3D Memory is a relatively small piece of DRAM sitting off to the side of the
GPU but yet on the same substrate. The Smart 3D Memory weighs in at only 10MB. Now the first
thing that you might think is, Well what the hell good is 10MB in the world of 512MB frame
buffers? And that would be a good line of questioning. The small 10MB of Smart 3D memory
that is currently being built by NEC will have an effective bus rate between it and the GPU of
2GHz. This is of course over 3X faster that what we see on the high end of RAM today.
Inside the Smart 3D Memory is what is referred to as a 3D Logic Unit. This is literally 192
Floating Point Unit processors inside our 10MB of RAM. This logic unit will be able to exchange
data with the 10MB of RAM at an incredible rate of 2 Terabits per second. So while we do not
have a lot of RAM, we have a memory unit that is extremely capable in terms of handling mass
amounts of data extremely quickly. The most incredible feature that this Smart 3D Memory will
deliver is antialiasing for free done inside the Smart 3D RAM at High Definition levels of
resolution. (For more of just what HiDef specs are, you can read about it here. Yes, the 10MB of
Smart 3D Memory can do 4X Multisampling Antialiasing at or above 1280x720 resolution without
impacting the GPU. Therefore, not only will all of your games on Xbox 360 be in High Definition,
but they also will have 4XAA applied.
The Smart 3D Memory can also compute Z depths, occlusion culling, and also does a very good
job at figuring stencil shadows. Stencil shadows are used in games that will use the DOOM 3
engine such as Quake 4 and Prey.
