Chaos Theory: SM2.0 vs SM3.0

[kylebisme]

Originally posted by: Gamingphreek
Well if Multi-Sampling doesn't work, would Super Sampling... im definitely thinking no; but wishful thinking?

Supersamping is just rendering at a higher resolution and outputting at a lower one, so yeah that can work with just about anything but it isn't very good for performnace. That is what I was referring to when I said mentioned software AA, You can see some pics of it in action here:
http://www.elitebastards.com/forum/viewtopic.php?p=157934

Originally posted by: GamingphreekWhat would they need to have done to update the AA scheme? In other words, what would all those transistors be used for?
-Kevin

To run multisampling at 16bit floating point precision instead of the 8bit integer precision that it works at now.

 

[Gamingphreek]

Wow... running SS and HDR would take SLI 7800's to run... yikes.

As for the 16bit precision. I assume FP over Integer would also bring performance increases as well as IQ increases as well as allowing for HDR and AA. Does ATI use the same thing as Nvidia there? What makes ATI's card so much more efficient at AA and AF than the Nvidia cards.

-Kevin

 

[Cuular]

If you look closely at the first set of photo's for the sm3.0 and sm2.0 in the article, you'll see that the ATI handles the "AA" part of the job better. Not meaning that AA is on with HDR, but the vertical and horizontal lines around the doors on the ATI are straight where the nvidia one has "jaggies". So on that one respect the nvidia loses the IQ fight. Whether or not being brighter is better or worse is up to personal taste.

Having 7800GTX SLI right beside an X850XT at home, there are definite IQ differences between them. And depending on what you are looking at ATI does some better and nvidia does the others better. Overall with latest cards nvidia definitely beats on speed, at resolutions 1600X1200 and above. And it looks damn good.

However some of the difference in IQ can be really noticeable and distracting. The most noticable is how it handles lighting and reflective surfaces. Especially in Half Life 2 and games using that engine. Both HL2 and Vampires:Bloodlines the peoples eyes look like mirrors on the nvidia, the light reflecting off them is to bright and reflected to much. On ATI it's a little more supressed and real looking. But then I can't run it at 1600X1200 with every single thing turned on on the ATI, and play with no slowdowns.

So The nvidia still gets the nod for actually catching up and then finally passing the ATI hardware. But I still like the IQ of ATI for certain things.

 

[Gamingphreek]

Originally posted by: Cuular
If you look closely at the first set of photo's for the sm3.0 and sm2.0 in the article, you'll see that the ATI handles the "AA" part of the job better. Not meaning that AA is on with HDR, but the vertical and horizontal lines around the doors on the ATI are straight where the nvidia one has "jaggies". So on that one respect the nvidia loses the IQ fight. Whether or not being brighter is better or worse is up to personal taste.

Having 7800GTX SLI right beside an X850XT at home, there are definite IQ differences between them. And depending on what you are looking at ATI does some better and nvidia does the others better. Overall with latest cards nvidia definitely beats on speed, at resolutions 1600X1200 and above. And it looks damn good.

However some of the difference in IQ can be really noticeable and distracting. The most noticable is how it handles lighting and reflective surfaces. Especially in Half Life 2 and games using that engine. Both HL2 and Vampires:Bloodlines the peoples eyes look like mirrors on the nvidia, the light reflecting off them is to bright and reflected to much. On ATI it's a little more supressed and real looking. But then I can't run it at 1600X1200 with every single thing turned on on the ATI, and play with no slowdowns.

So The nvidia still gets the nod for actually catching up and then finally passing the ATI hardware. But I still like the IQ of ATI for certain things.

I dont think that is an IQ advantage. I think that is a personal preference (not to ATI but to the Image). For instance some people do not care for HDR, but it is still intended to be an IQ enhancing feature.

-Kevin

 

[Munky]

Originally posted by: Gamingphreek
Wow... running SS and HDR would take SLI 7800's to run... yikes.

As for the 16bit precision. I assume FP over Integer would also bring performance increases as well as IQ increases as well as allowing for HDR and AA. Does ATI use the same thing as Nvidia there? What makes ATI's card so much more efficient at AA and AF than the Nvidia cards.

-Kevin

AFAIK, FP formats are actually more demanding to run than integers, but they do result in increased accuracy, and thus better IQ. I also know that ever since the original radeon, Ati had a habit of optimising their cards for high resolutions and AA/AF. For example, the x800xt with 16 pipes can do 16 fragment operations in a single pass, but it also can do 32 z-buffer operations per pass without color (when doing shadows for example) BUT only when AA is enabled.

I also think there's abunch of other reasons for this inherent in the design of the r300 architecture, because ever since the 9700 cards, Ati seemed to pull ahead of the competition whenever AA and AF are enabled.

 

[Drayvn]

If im right AA and AF is calculated mathematically, and i always thought the Radeon cards were better at maths operations?

Also about the FP stuff, isnt that because the FP blending is rendered AFTER the AA is produced, meaning that if you wanted HDR it had to disable it because it would conflict, and if thats right it would be a hardware problem?