Anisotropic Filtering

The NVIDIA 6xxx series uses a different algorithm for Anisotropic Filtering. AF on the 6xxx cards appears to be working fine. There is a clear difference between each setting.

AF Setting Image
(click to enlarge)
Difference Map
(click to enlarge)
No AF -
2X AF
4X AF
8X AF
16X AF

Below, you can see the image quality difference between the image with no AF, the image with 2X AF, and the image with 16X AF.



No AF. Hold your mouse over image to see 2X AF.




2X AF. Hold your mouse over image to see 16X AF.




No AF. Hold your mouse over image ti see 16X AF.


There is a very clear difference here between the various AF levels, unlike on the 5xxx series cards. We have a chart indicating the various frames per second for each AF setting under the GeForce 6800 in 1280x1024 mode.

Linux AF Scaling - GeForce 6800

Performance drops as much as 25% moving from 1X (No) AF to 16X AF. There does not appear to be a definitive sweet spot, since the graph scales very linearly.

Image Quality, AF, Trial 1 Final Thoughts
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  • Guspaz - Thursday, October 14, 2004 - link

    I'm sorry, I snapped. The tone of my post was uncalled for.

    I still believe, however, that further investigation is in order.
  • LittleKing - Thursday, October 14, 2004 - link

    I've said it before and I'll say it again, the rollover images don't work with FireFox. It's a shame Anand won't support it I guess.

    LK
  • KristopherKubicki - Wednesday, October 13, 2004 - link

    Guspaz: We get different frame rates with 8X and 16X. Even if they produce the same image, I suspect they use different algorithms. I don't know why that would seem unprofessional?

    Kristopher
  • walmartshopper - Wednesday, October 13, 2004 - link

    #20... If it's not doing 16x, how do you explain the performance drop? Just because the images are the exact same does not mean it's not doing the work. Theres a limit to antialiasing, meaning there's a limit to how smooth an edge can be. I think in many cases, 8x hits that limit, and 16x is just overkill. But just because there's no difference in this particular screenshot doesn't mean theres not ever a difference. I'm sure it makes some kind of difference in most cases, even if only a few pixels. Just imagine if 32xAA existed... compare 16x to 32x and i doubt you would ever be able to find any difference. But that doesn't mean the card isn't doing extra work. With 8x and 16x you are starting to get into the same territory where anything above 8x makes little or no difference.

    Sorry, but that post gave me a good laugh.
  • sprockkets - Wednesday, October 13, 2004 - link

    Keep in mind that SuSE uses xfree86 in 9.1and will go to x.org in the next release, or it seem by the way the ftp is hinting it will.
  • walmartshopper - Wednesday, October 13, 2004 - link

    I'm getting noticably better performance on Linux over xp. I run 1600x1200 high quality with 4xAA on a 6800gt.

    Linux:
    Slackware 10
    kernel: custom 2.6.8.1
    X: xorg 6.8
    NV driver: 6106
    Desktop: KDE 3.3 (4 desktops, 4 webcam monitors, amsn, gaim, desktop newsfeeds, and a kicker loaded with apps all running while i play)

    xp:
    fresh copy with nothing more than a few games installed
    NV driver: 66.72

    At the same settings, the game feels noticably smoother on linux. Thanks to ReiserFS, the loading time is also much faster. Sorry for no benchmarks, but I got rid of the windows install after my first time playing on Linux. I had problems with the 6111 driver crashing, but 6106 works flawlessly. (Although I can switch drivers in less than a minute without even rebooting) I can't wait until nvclock supports overclocking on the 6800 series.

    I'm a little disappointed that all the testing was done on SuSE. The beauty of Linux is being able to customize and optimize just about anything. I realize that SuSE is a distro that average joe is likely to use, but I think you should also include some scores from a simple, fast, optimized distro/kernel such as Slack or Gentoo to show what Linux is really capable of.

    3500+ @ 2.44ghz
    1gb ddr @ 444mhz 2.5-3-3-7
    k8n neo2 platinum
  • Guspaz - Wednesday, October 13, 2004 - link

    I did a difference on the 8x and 16x AA images.

    You're wrong. Your review cards are NOT doing 16xAA. They're doing 8xAA.

    Considering how the 8x and 16x images look identical, that should have been your first hint; once you run a diff and find they ARE identical, I'd expect you to know better.

    Seriously, make a correction, this looks unprofessional.
  • Saist - Wednesday, October 13, 2004 - link

    #15 - My bad to make such generalizations..

    but the fact that you can't even use an ATI card to play D3 doesn't bode well for Linux gaming...

    ****

    Keep in mind, ATi is several months, if not a year or more behind Nvidia in supporting Linux. Give ATi time, and things like this will probably become as obsolete as Win95.
  • Olias - Wednesday, October 13, 2004 - link

    At 800x600-high quality, I get 32fps in XP and 45 in Linux. Linux is 13fps(40%) faster.

    AMD Athlon XP 3200+
    nForce2 chipset
    5900XT Video Card
    Memory: 2x512MB PC-3200 CL2.5 (400MHz)
    Distro: Gentoo Linux
    Kernel: 2.6.7-r14
    X: xorg-x11-6.7.0-r2
  • ath50 - Wednesday, October 13, 2004 - link

    You list on the first page

    "Timothee Besset, Linuxgamers.com " as the source of the quote, but its actually Linuxgames.com, linuxgamers is one of those search pages with popups that tries to reset your homepagge :

    Just a little thing...I went off to linuxgamers.com first hehe.

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