ATI's Late Response to G70 - Radeon X1800, X1600 and X1300
by Derek Wilson on October 5, 2005 11:05 AM EST- Posted in
- GPUs
High Quality AF
One of the greatest things about the newest high end hardware from NVIDIA and ATI is that advanced filtering features can be enabled at any resolution while still maintaining playable framerates. It may take developers a little while to catch up to the capabilities of the X1800 and 7800 lines, but adding value through advanced quality features is definitely a welcome path for ATI and NVIDIA to take. For this launch, ATI has improved their AA and AF implementations. We also have two brand new features: Adaptive AA and Area Anisotropic filtering.
Starting with Area Anisotropic (or high quality AF as it is called in the driver), ATI has finally brought viewing angle independent anisotropic filtering to their hardware. NVIDIA introduced this feature back in the GeForce FX days, but everyone was so caught up in the FX series' abysmal performance that not many paid attention to the fact that the FX series had better quality anisotropic filtering than anything from ATI. Yes, the performance impact was larger, but NVIDIA hardware was differentiating the Euclidean distance calculation sqrt(x^2 + y^2 + z^2) in its anisotropic filtering algorithm. Current methods (NVIDIA stopped doing the quality way) simply differentiate an approximated distance in the form of (ax + by + cz). Math buffs will realize that the differential for this approximated distance simply involves constants while the partials for Euclidean distance are less trivial. Calculating a square root is a complex task, even in hardware, which explains the lower performance of the "quality AF" equation.
Angle dependant anisotropic methods produce fine results in games with flat floors and walls, as these textures are aligned on axes that are correctly filtered. Games that allow a broader freedom of motion (such as flying/space games or top down view games like the sims) don't benefit any more from anisotropic filtering than trilinear filtering. Rotating a surface with angle dependant anisotropic filtering applied can cause noticeable and distracting flicker or texture aliasing. Thus, angle independent techniques (such as ATI's area aniso) are welcome additions to the playing field. As NVIDIA previously employed a high quality anisotropic algorithm, we hope that the introduction of this anisotropic algorithm from ATI will prompt NVIDIA to include such a feature in future hardware as well.
We sat down with the D3DAFTester to show the difference between NVIDIA and ATI hardware with and without the high quality mode enabled. Here's what we ended up with:
One of the greatest things about the newest high end hardware from NVIDIA and ATI is that advanced filtering features can be enabled at any resolution while still maintaining playable framerates. It may take developers a little while to catch up to the capabilities of the X1800 and 7800 lines, but adding value through advanced quality features is definitely a welcome path for ATI and NVIDIA to take. For this launch, ATI has improved their AA and AF implementations. We also have two brand new features: Adaptive AA and Area Anisotropic filtering.
Starting with Area Anisotropic (or high quality AF as it is called in the driver), ATI has finally brought viewing angle independent anisotropic filtering to their hardware. NVIDIA introduced this feature back in the GeForce FX days, but everyone was so caught up in the FX series' abysmal performance that not many paid attention to the fact that the FX series had better quality anisotropic filtering than anything from ATI. Yes, the performance impact was larger, but NVIDIA hardware was differentiating the Euclidean distance calculation sqrt(x^2 + y^2 + z^2) in its anisotropic filtering algorithm. Current methods (NVIDIA stopped doing the quality way) simply differentiate an approximated distance in the form of (ax + by + cz). Math buffs will realize that the differential for this approximated distance simply involves constants while the partials for Euclidean distance are less trivial. Calculating a square root is a complex task, even in hardware, which explains the lower performance of the "quality AF" equation.
Angle dependant anisotropic methods produce fine results in games with flat floors and walls, as these textures are aligned on axes that are correctly filtered. Games that allow a broader freedom of motion (such as flying/space games or top down view games like the sims) don't benefit any more from anisotropic filtering than trilinear filtering. Rotating a surface with angle dependant anisotropic filtering applied can cause noticeable and distracting flicker or texture aliasing. Thus, angle independent techniques (such as ATI's area aniso) are welcome additions to the playing field. As NVIDIA previously employed a high quality anisotropic algorithm, we hope that the introduction of this anisotropic algorithm from ATI will prompt NVIDIA to include such a feature in future hardware as well.
We sat down with the D3DAFTester to show the difference between NVIDIA and ATI hardware with and without the high quality mode enabled. Here's what we ended up with:
NVIDIA 7800 GTX AF
NVIDIA 7800 GTX AF
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DigitalFreak - Wednesday, October 5, 2005 - link
CPU limited?DRavisher - Wednesday, October 5, 2005 - link
Usually you are not CPU limited at such high resolutions. Though it would of course be possible. But my comment still stands; the XT is not showing any good scaling at higher resolutions in those benchmarks, rather the opposite.raj14 - Wednesday, October 5, 2005 - link
i am not surprised, with 16 Pixel pipelins everybody knowed ATi was going to loose, ATi has Always sucked and continues to do so. even in Cross-FIre radeon 1800XTs won't come near SLied 7800GTXs. hats off to NVIDIA and thumbs down to ATi.utube545 - Tuesday, June 12, 2007 - link
Fuck off you dumbassmlittl3 - Wednesday, October 5, 2005 - link
Excerpt from extremetech.com review of the X1800:"The Radeon X1800 XT fares much better against the GeForce 7800 GTX. It is faster, on the whole, whether you apply AA and AF or not (though the difference is tiny without them). The only reason the 7800 GTX remains less than 20% behind is because of the dominance of Nvidia in Doom 3. Without that game, ATI pulls even further ahead."
"With 8 fewer pixel pipelines, it's impressive to see this difference in performance, even though the X1800 XT runs at a much higher clock speed. We question whether it can be attributed to all the improvements in the new architecture for the sake of per-pipeline efficiency, or if it has more to do with the 25% advantage in memory bandwidth."
The 16 pipes vs. 24 pipes is not enough to draw a conclusion. At this site, the ATI cards wins with 16 pipes in most cases.
Griswold - Wednesday, October 5, 2005 - link
I'm guessing you got your first PC last christmas.
LoneWolf15 - Wednesday, October 5, 2005 - link
Too bad he didn't get his first Speak `n Spell last Christmas, it would have been a more useful gift.mlittl3 - Wednesday, October 5, 2005 - link
I don't understand how Anandtech can complain about no products at launch when they post live review articles when they aren't even remotely ready. I know you guys are doing it because you want to post the article when the other sites do but if it isn't ready, it isn't ready. Come on. You are doing the exact same thing as ATI's paper launches.You have graphs showing the X1800xl beating x1800xt. You say there is good scaling with AA enabled but you don't show the data without AA. You also only tested like 5 games. Where is the 3dmark benches? Where are all the other games?
Anandtech review launch = ATI paper launch
I'm going to another review site. This is abysmal.
mlittl3 - Wednesday, October 5, 2005 - link
Oh and one other thing. The cards picked for each section: budget, midrange, highend seem randomly chosen. Why don't we have 9200, x300, 5200, 6200, x1300 in the low end? 9600, x600, 5600, 6600, x1600 in the mid range? And 9800, x800, 5900, 6800, x1800, 7800 in the high-end? If you can't go back two generations of cards, then show some of the derivatives of last generation at least (xl, xt, xt pe, pro, ultra, etc.). Everything is so scatter-brained here no one can tell what card is faster than what.Go to extremetech.com. They show the ATI cards winning in almost every single test and they also have 3dmark scores. ATI did a great job with 16 pipelines and gives almost 1.5x performance over x800 series and beats the 7800. Don't use this site to determine the winner. Go to multiple sites.
bob661 - Wednesday, October 5, 2005 - link
So you only look for benchmarks that show what you want to see? Besides, I checked extremetech.com and ATI did NOT win all of the benchmarks there. 2 fps is not a win as you will NEVER be albe to tell the difference. Besides, how the hell is 2 fps or even 10 fps worth $100?