Angle-Independent Anisotropic Filtering At Last

For a number of years now the quality of anisotropic filtering has been slowly improving. Early implementations from AMD and NVIDIA were highly angle-dependent, resulting in a limited improvement to image quality from such filtering. The angle-dependent nature lead to shimmering and other artifacting that was not ideal.

As of the previous generation of cards, the quality of anisotropic filtering had become pretty good. NVIDIA’s best filtering mode was pretty close to angle-independent, and AMD’s only slightly worse. Neither was perfect, but neither was bad either.


The Radeon HD 4890


The GeForce GTX 285

However so long as no one had an angle-independent implementation, there was room to improve. And AMD has gone there. The anisotropic filtering algorithm used by the 5000 series is now truly and completely angle-independent. There are no more filtering tricks being used.


The Radeon HD 5870: Perfection

As you can see, the MIP maps in our venerable D3D AF Tester are perfectly circular, the hallmark of an angle-independent implementation. With angle-independent filtering, this effectively marks the end of the filtering arms race. AMD has won, and should NVIDIA catch up in the future the two would merely be tied. There’s nowhere left to go for quality beyond angle-independent filtering at the moment.

AMD tells us that there is no performance hit with their new algorithm compared to their old one. This is a bit hard to test since we can’t enable the old algorithm on the 5870, but certainly whatever performance hit there is, is similarly minor. In all of the testing we’re doing today, you will see results done with 16x anisotropic filtering used.

What you won’t see however is a difference, particularly with our static screenshots. When discussing the matter, AMD noted that the difference in perceived quality between the old algorithm and the new one was practically the same. After looking at matters we find ourselves in agreement with AMD; we were not able to come up with any situations where there was a noticeable difference, beyond the obvious AF quality tests that are designed to identify such changes.

Regardless of the outcome, AMD deserves kudos for making angle-independent anisotropic filtering happen. It’s demonstrably perfect filtering with no speed hit versus the previous generation of filtering; making it in essence a “free” improvement in image quality, however slight the real-world results are. We’re always ready to get better image quality out of our video cards, after all.

More GDDR5 Technologies: Memory Error Detection & Temperature Compensation The Return of Supersample AA
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  • pinguin - Monday, September 28, 2009 - link

    It IS a hard launch as obviously a few cards are available. That consumers rip them off one's hand is another problem...

    Anyway I'll wait until the 5650: 4850 performance w/o PCIe connector + DX11: I'm coming! What else do I need to show off to my friends still staying with rebranded G92 chips!!
    Reply
  • jabroni619 - Friday, September 25, 2009 - link

    I guess it is, it was even better still when I decided to come home a bit early and UPS got there 2 hours sooner than they usually do. Playing through Crysis Warhead once more "The way it's meant to be played" on an ATI card though.

    Also included was a Dirt 2 code to be activated on steam, which I nearly threw out! Now I just have to wait for the game to be released.
    Reply
  • camylarde - Thursday, September 24, 2009 - link

    Lol. I was horrified, when i heard that my precious badminton racquet purchased on my friends address in england was "delivered" to the front door, waiting for him all day on the doorstep.

    if the card is gonna wait for you in a similar fashion, may i get to know where do you live to... erm... be there when you open the box and celebrate with you?

    [/envy]
    Reply
  • SiliconDoc - Wednesday, September 23, 2009 - link

    I'm not certain how you saw any available then, looks from 3 different states didn't show that.
    Heck they weren't even active at 8 am, nor later than that. I guess you "got the only one" that wasn't Autonotify when arriving.
    Reply
  • The0ne - Wednesday, September 23, 2009 - link

    This is the last piece of hardware I've been waiting for before I build my i7 system. Now I think it's a ok time for enthusiast to start building again but on a cheaper budget with better performance :) no more of these 200-300 MB and stuff lol Reply
  • gwolfman - Wednesday, September 23, 2009 - link

    I agree. Full bit-streaming support! Yeaz! Reply
  • blanarahul - Wednesday, December 21, 2011 - link

    They should have given the option for 5870 to have triple DVI rather than single DVI + Dual DP. :( Reply

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