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
Mouse over to cycle images
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ChanningM - Wednesday, October 5, 2005 - link
Where is the AA info and AF info on each test?You list 4x AA for the High End cards at 1600x1200. What about other levels of AA, and various levels of AF?
What about other resolutions? and varying levels of AA and AF at different resolutions and how they compare image quality wise? Okay, so the X1600XT loses at 1280x960 with no aa or af. What about at 1028x764 with AA and AF on? And how does that compare image wise?
Where is the discussion of the results? You just throw out graphs at me, and don't do a real disucssion of them.
In otherwords, where is the rest of the review?
Peldor - Wednesday, October 5, 2005 - link
At this point, a fairly weak review from Anandtech, especially compared to the 7800GTX review when it appeared. Hot Hardware and Tech Report have a bit better coverage IMO.Looking at other reviews around the web, my conclusion is the X1800 cards are viable competitors in performance to the 7800 cards, but the street prices will have to come down near the 7800 cards to be a good value.
The X1600 cards look dead in the water when the 6600GT is under $150 and available in AGP and PCIe, while the 6800GT is far beyond it in the ~$250 segment.
The X1300 cards will only survive in the ~$100 and under market.
ATI is going to need that R580 sooner rather than later.
ChanningM - Wednesday, October 5, 2005 - link
The format of the hardocp articles has grown on me, especially after reading there review + the anandtech + another.There are all kinds of AA and AF options for a reason. They look different. How do the affect peformance though? What works best?
That obviously varies by game, card and resolution. But anandtech and others just don't do the comparisons and I think that makes it difficult to compare. Especially when image quality differences between nvidia and ATI come into play with there various settings.
DerekWilson - Wednesday, October 5, 2005 - link
We will have tables of all the data with all the numbers we ran across all the resolutions with 4xAA and 8xAF up shortly.Quite a bit of data was collected and it has taken some time to organize. You are absolutely right to want more, and we are working on getting it out the door as soon as possible.
Thanks,
Derek Wilson
jeffrey - Wednesday, October 5, 2005 - link
Derek,You really need to evaluate your situation at this website. You are listed as "author" of the "NVIDIA's GeForce 7800 GTX Hits The Ground Running" and "ATI's Late Response to G70 - Radeon X1800, X1600 and X1300" articles. Both of these articles are not up to Anandtech standards and have prompted numerous posts for readers to visit other websites.
I am a long-time reader of the site and am only posting this because I don't want to go anywhere else. I just don't believe that your articles have been up to snuff. The posts for proofreading, wrong labels, incomplete data, etc keep appearing and back up my opinion.
If Anand did not finish your mentoring, please let him know. I know that you put a lot of time and effort into this site, but the two biggest articles of the year for GPU's have left me shaking my head in dissapointment. Please work more with Anand, or do your own homework and read some of his old reviews. If you need another person, or co-author to help you ...please swallow your pride and ask for it.
Respectfully,
Jeffrey
drifter106 - Thursday, October 6, 2005 - link
What credentials do you have to make such an accusation? What indicators do you use to support such a statement? On the contrary, considering the time frame and the rush to provide us with information it is obvious for the coherent, that he has done a good job. Glad to see information provided that will futher support my next video card selection.erinlegault - Thursday, October 6, 2005 - link
That is exactly the point! He shouldn't be rushing. The Techreport and Xbit Labs and many others offer much more informative reviews.Do you want my credentials? It shouldn't matter a report is a report is a report. You don't have to have a PhD or be a CEO to have an opinion. Any person with a University or College degree knows how to write a report that is complete and accurate.
The fact of the matter is Anand's graphics reviews have been not up to par. Period.
Tamale - Saturday, October 8, 2005 - link
lol.. the 'fact' is that this 'opinion' isn't up to 'my standards'sounds like a real fact, folks.. this guy is serios business
Madellga - Wednesday, October 5, 2005 - link
http://www.overclockers.co.uk/acatalog/X1800_Serie...">http://www.overclockers.co.uk/acatalog/X1800_Serie...AdamK47 3DS - Wednesday, October 5, 2005 - link
I absolutly hate obvious marketing fluff!"16 ultra efficient extreme pipelines"
Those pipelines are about as extreme as a peanut butter and jelly sandwich is extreme. Try harder next time Ati!