![[H]ardOCP](/images/blank.gif){kind=small}
- Date:
- Tuesday , September 21, 2004
- Author:
- Brent Justice
- Editor:
- Kyle Bennett
- Google +1
ATI Radeon X700XT Preview
ATI introduces their mainstream video card series based on flagship X800 technology and we take a look at what level of gaming experience the Radeon X700XT is delivering directly compared to NVIDIA's GeForce 6600GT.
CATALYST A.I.:
Application detection and texture filtering optimizations are here to stay. There, we’ve said it. These are two terms that many video enthusiasts cringe over hearing. You see though, these things are not going to go away, in fact they are going to become very real to you.
We’d like everyone reading this to think about this question for a moment. Do you want your games to perform better, be more stable, and do all of this without changing image quality or possibly making it better? If you are a gamer, the answer to this is going to be a resounding "YES." This is ATI's goal. ATI also has a method for that goal and it is called CATALYST A.I.
As the name implies, CATALYST A.I. is an "Artificial Intelligence" algorithm performed by the video card drivers on games. This Intelligence will analyze your games and the textures in those games to maximize graphics performance and maintain stability while still delivering the highest image quality.
This will be a new slider feature in an upcoming version of CATALYST Control Center. You must have the CATALYST Control Center installed in order to access this new slider. It will not be in the legacy control panel. If you do not install the new CATALYST Control Center, CATALYST A.I. will be enabled by default at the "Standard" setting in the drivers and you will not be able to turn it off or select the "Advanced" setting.
It is important to realize that this optimization has the potential to improve performance as well as image quality, so it is not a performance increasing only feature. ATI has a software algorithm that uses your CPU to do the calculations and is able to analyze individual textures to find the best way to display them on ATI video cards. Because this uses your CPU to do this analyzing it does have the potential to decrease performance at low resolution CPU dependent settings or in heavily CPU dependent games at low resolutions. This feature works best when the game is video card bound at high resolutions.
Concerning the "High" CATALYST A.I. setting, we have a quote from ATI's Jon Carvill that explains another scenerio in which it could decrease performance.
"A possible performance hit could occur in an application that continuously loads textures without a break in game play (a scrolling game like dungeon siege) – we never actually saw a performance hit but as the algorithm is much more aggressive on the “high” setting, it could in theory cause a slow down on low end systems – obviously we were unable to test every game out there, so just to be sure we put in two settings (low and high) we know that low will only improve performance, and with 99% certainty we know that “high” will improve performance even more, but there could be a really odd circumstance where it degrades performance."
"Basically we have two types of optimizations enabled within CATALYST AI (generic optimizations anyways) for texture filtering and anisotropic filtering – we’re always going to try and do as little work as possible as long as it doesn’t affect image quality (i.e. meaning use bilinear filtering instead of trilinear filtering when the results look identical, or taking less samples when doing anisotropic filtering – again why take say 16 samples when you can take 8 samples for certain textures when the results look identical). So moving the CATALYST AI slider from low to high just makes that algorithm more aggressive."
In theory, this idea is a good one. Some games simply aren’t optimized correctly for certain video cards; the game may perform poorly on it. With this feature ATI is able to analyze the textures and make them display the best way on their video card.
These optimizations are able to be carried out through application detection. Again, this is not inherently a bad thing. If used correctly, such as ATI is proposing, it can bring about a more stable gaming environment, improved performance, or even improved image quality. Let’s say for instance there is a game bug that deals with a graphics card. A video card manufacturer may be able to create the fix for this bug in their drivers and when it detects the game being run will fix this bug allowing better gameplay. In theory the idea is sound and can only improve a gamer's experience in games.
With the CATALYST driver and Control Center we are using here today, ATI is currently detecting for DOOM 3, UT2003/4, the Half Life 2 engine, Splinter Cell, Race Driver, Prince of Persia, and Crazy Taxi 3. More games will follow as ATI figures out the best way to render and display popular games on their video cards.
On DOOM 3
In DOOM 3, ATI is currently implementing a mathematically correct shader replacement that has to deal with lighting. This shader replacement improves performance while maintaining the same image quality.
Interestingly enough, we pinged John Carmack on this issue and asked what he thought about shader replacement in DOOM 3 and in general.
However, I do realize that it seems to be pretty much inevitable for popular programs. Nvidia seems to have some very Doom-fragment-program specific optimizations in the NV30 driver paths, so I wouldn't single out ATI over it."
On Unreal Tournament
To learn what ATI is doing in UT2003 and UT2004, we have a statement from ATI's Jon Carvill:
"Unreal Tournament 2003/Unreal Tournament 2004: The CATALYST driver has been modified so that the anisotropic filtering type (bilinear, trilinear, or a combination of both) is now always determined by the application. In previous CATALYST drivers (for all Direct3D applications) if the user enabled “quality” anisotropic filtering, only the first stage of textures had trilinear filtering applied, whereas the rest of the texture stages had bilinear filtering applied. Starting with CATALYST 4.10 the filtering type used on each stage is now solely determined by the application. For Unreal Tournament 2003 and Unreal Tournament 2004 CATALYST A.I. performs an advanced level of texture analysis (on all RADEON X Series products) to provide significantly higher performance levels with no distinguishable difference in image quality. The RADEON 9800, RADEON 9700, and RADEON 9500 Series of products will continue to use the anisotropic filtering “Quality” mode found in earlier CATALYST releases when CATALYST A.I. is enabled."
So this basically means for Radeon X series products the drivers will now let the application decide what texture stages get what filtering.
User Control and Usage Features
Finally ATI has listened to gamers and have given them full control over these optimizations. CATALYST A.I. can be easily disabled if you do not wish for the driver to do application detecting or texture filtering optimizations. ATI wants you to know that they will never application detect for synthetic benchmarks. This is a game only feature.
Like we said, the ideas are sound. All gamers want is faster performance, stability, and increased image quality. CATALYST A.I. has the potential to make this happen on ATI based video cards.
Yes, with application detection this means shader replacement is a possibility in order to make these changes happen. As a gamer, however you feel about this, the facts can’t be denied that if a shader replacement brings forth the SAME (key word SAME) image quality and improves performance, then there is nothing wrong with it from a gamer's perspective.
There are two slider positions for CATALYST A.I. in CATALYST Control Center, Standard and Advanced. The default setting is Standard. The Advanced Setting provides a more aggressive approach at the optimizations, and of course you can disable this feature all together if you wish. On the following pages we will look at the performance between each slider setting as well as image quality.