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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  • maomao0000 - Sunday, October 11, 2009 - link

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  • shaolin95 - Wednesday, October 7, 2009 - link

    So Eyefinity may use 100 monitors but if we are still gaming on the flat plant then it makes no difference to me.
    Come on ATI, go with the real 3D games already..been waiting since the Radeon 64 SE days for you to get on with it.... :-(
    GTX 295 for this boy as it is the only way to real 3D on a 60" DLP.

    Nice that they have a fast product at good prices to keep the competition going. If either company goes down we all lose so support them both! :-)

    Regards
    Reply
  • raptorrage - Tuesday, October 6, 2009 - link

    wow what a joke this review is but that i mean the reviewer stance on the 5870 sounds like he is a nvidia fan just because it like what 2-3fps off of the gtx 295 doesn't actually mean it can't catch that gpu as the driver updates come out and get the gpu to actually compete against that gpu and if i remember wasn't the GTX 295 the same when it came out .. its was good but it wasn't where we all thought it should have been then BAM a few months go by and it finds the performance it was missing

    i don't know if this was a fail on anandtech or the testing practices but i question them as i've read many other review sites and they had a clear view where the 5870 / GTX 295 where neck N neck as i've seen them first hand so i go ahead and state them here head 2 head @ 1920x1200 but at 2560x1600 the dual gpu cards do take the top slot but that is expected but it isn't as big as a margin as i see it.

    and clearly he missed the whole point YES the 5870 dose compete with the GTX 295 i just believe your testing practices do come into question here because i've seen many sites where they didn't form the opinion that you have here it seems completely dismissive like AMD has failed i just don't see that in my opinion - I'll just take this review with a gain of salt as its completely meaningless
    Reply
  • dieselcat18 - Saturday, October 3, 2009 - link

    @Silicon Doc
    Nvidia fan-boy, troll, loser....take your gforce cards and go home...we can now all see how terrible ATi is thanks you ...so I really don't understand why people are beating down their doors for the 5800 series, just like people did for the 4800 and 3800 cards. I guess Nvidia fan-boy trolls like you have only one thing left to do and that's complain and cry like the itty-bitty babies that some of you are about the competition that's beating you like a drum.....so you just wait for your 300 series cards to be released (can't wait to see how many of those are available) so you can pay the overpriced premiums that Nvidia will be charging AGAIN !...hahaha...just like all that re-badging BS they pulled with the 9800 and 200 cards...what a joke !.. Oh my, I must say you have me in a mood and the ironic thing is I do like Nvidia as much as ATi, I currently own and use both. I just can't stand fools like you who spout nothing but mindless crap while waving your team flag (my card is better than your's..WhaaWhaaWhaa)...just take yourself along with your worthless opinions and slide back under that slimly rock you came from.

    Reply
  • dieselcat18 - Saturday, October 3, 2009 - link

    @Silicon Doc
    Nvidia fan-boy, troll, loser....take your gforce cards and go home...we can now all see how terrible ATi is thanks you ...so I really don't understand why people are beating down their doors for the 5800 series, just like people did for the 4800 and 3800 cards. I guess Nvidia fan-boy trolls like you have only one thing left to do and that's complain and cry like the itty-bitty babies that some of you are about the competition that's beating you like a drum.....so you just wait for your 300 series cards to be released (can't wait to see how many of those are available) so you can pay the overpriced premiums that Nvidia will be charging AGAIN !...hahaha...just like all that re-badging BS they pulled with the 9800 and 200 cards...what a joke !.. Oh my, I must say you have me in a mood and the ironic thing is I do like Nvidia as much as ATi, I currently own and use both. I just can't stand fools like you who spout nothing but mindless crap while waving your team flag (my card is better than your's..WhaaWhaaWhaa)...just take yourself along with your worthless opinions and slide back under that slimly rock you came from.

    Reply
  • Scali - Thursday, October 1, 2009 - link

    I have the GPU Computing SDK aswell, and I ran the Ocean test on my 8800GTS320. I got 40 fps, with the card at stock, with 4xAA and 16xAF on. Fullscreen or windowed didn't matter.
    How can your score be only 47 fps on the GTX285? And why does the screenshot say 157 fps on a GTX280?
    157 fps is more along the lines of what I'd expect than 47 fps, given the performance of my 8800GTS.
    Reply
  • Ryan Smith - Thursday, October 1, 2009 - link

    Full screen, 2560x1600 with everything cranked up. At that resolution, it can be a very rough benchmark.

    The screenshot you're seeing is just something we took in windowed mode with the resolution turned way down so that we could fit a full-sized screenshot of the program in to our document engine.
    Reply
  • Scali - Friday, October 2, 2009 - link

    I've just checked the sourcecode and experimented a bit with changing some constants.
    The CS part always uses a dimension of 512, hardcoded, so not related to the screen size.
    So the CS load is constant, the larger you make the window, the less you measure the GPGPU-performance, since it will become graphics-limited.
    Technically you should make the window as small as possible to get a decent GPGPU-benchmark, not as large as possible.
    Reply
  • Scali - Friday, October 2, 2009 - link

    Hum, I wonder what you're measuring though.
    I'd have to study the code, see if higher resolutions increase only the onscreen polycount, or also the GPGPU-part of generating it.
    Reply
  • Scali - Thursday, October 1, 2009 - link

    That's 152 fps, not 257, sorry. Reply

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