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  • Initial impressions of ATI's drivers...

    These aren't great, but they're WAY better than they used to be.

    Some background. I care about precisely three applications:
    * xterm
    * firefox
    * World of Warcraft

    That's it. xterm and firefox work everywhere, so the only interesting thing, to me, is WoW performance.

    Some years back, I had... Hmm. Probably a Radeon 9600 or so. Maybe a 9800. Anyway, I had that on a Windows box, and I was doing some WoW addon development, and I was really hating the Windows experience -- such as the 5 second lag to resync my monitor when I changed from 1600x1200, 60Hz, to 1600x1200, 60Hz. Whatever.

    So I rebooted to Linux, copied some files over, and tried WoW. It ran great... Until I found problems, such as "1 second lag upon changing target" or "1 second lag upon any of a large number of video effects".

    After reading reviews, forum posts, and so on, I went out and picked up a GeForce 7950, swapped drivers, and... It was flawless. Worked better, ran faster. Huge upgrade.

    Since then, I've gone through about 4 nVidia cards, all of which have been livable. There was one brief period where fog rendering got completely broken, which lasted for about one minor driver update.

    Anyway, it's been a while, and I had heard that ATI's drivers were a lot better, so I decided to get a 5750 fanless card (I'm big on fanless cards) and see how it worked.

    Initial impressions:

    * The install process is pretty livable. It worked, anyway.
    * The driver is not especially stable in the face of the sorts of changes one can make through the UI.
    * Especially not in DirectX.
    * OpenGL works.
    * I don't think this card should be noticably slower than a GeForce 9800GT. But it is.

    The most impressive example I got of a Just Plain Crazy failure mode is that enabling full screen glow in DirectX mode causes the entire 3D view to flip upside down. I can't even dignify that with such language as "doesn't make any sense". That's just insane. (Note that the nVidia drivers I used most recently couldn't do full screen glow in directx mode either.)

    The card makes a bit of a high-pitched whine; I'm told that's common on new hardware (indeed, that's why I don't have a GeForce 260 right now -- this one isn't nearly as bad).

    I've had three or four cases where wine dropped into a debugger upon an attempt to change some UI feature. Ugh.

    Overall impressions:
    * Way, WAY better than it was four years ago.
    * Could definitely use work, both on stability and performance.
    * The hardware price/performance/power requirements look to have improved a lot.

    I'm easily annoyed by fan noise and the like, but the big thing to me is that I'm sort of disappointed by the performance. I'd expect a card a full year or so newer to be at least marginally faster, and on paper, the 5750 looks like it should be noticably faster, or at least not particularly slower, than the 9800GT. In practice, it's about 20% slower, maybe a bit more.

    Two years ago, I would not have recommended even trying ATI's Linux drivers. Now, well, they're still clearly second-place, but they're a lot closer. The substantial edge in wattage is pretty attractive, too.

    I do wonder where all the time is going, though. There is no reason for a modern system to be running <30fps in low-population old-world parts of WoW.

  • #2
    Not everything you mentioned is caused by the gfx driver; some of those problems are simply wine-bugs. fglrx does not support DirectX, neither do nvidia's drivers. That's handled by wine.
    Wine uses different code depending on the driver and it's advertised capabilities, it's quite possible that you're running into different code-paths that aren't well tested or simply buggy.
    Figuring out which part is responsible for a certain bug isn't easy, though.

    But yeah, wine + fglrx isn't the best combination. Wine's DirectX layer was initially developed on nvidia-hardware, it's not really optimized for fglrx. It's making progress, but not as much as you might hope.
    You might improve performance with some wine settings (the defaults are often targeted to nvidia), there may be tips here:
    http://appdb.winehq.org/objectManage...ation&iId=1922

    In any case, statements about a card's performance that are solely based upon WoW on wine are a bit lopsided. The 5750's hardware is a bit faster than the 9800GT, but not much - you're comparing a mid-level card of the current generation with a high-end card of the last. It's slower in your use case due to driver differences.

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    • #3
      Originally posted by rohcQaH View Post
      You might improve performance with some wine settings (the defaults are often targeted to nvidia), there may be tips here:
      http://appdb.winehq.org/objectManage...ation&iId=1922
      I have some.

      In any case, statements about a card's performance that are solely based upon WoW on wine are a bit lopsided. The 5750's hardware is a bit faster than the 9800GT, but not much - you're comparing a mid-level card of the current generation with a high-end card of the last. It's slower in your use case due to driver differences.
      True.

      On the other hand... It hasn't crashed yet (except when messing with video settings, which I expect to be dodgy), and it runs about 20W less power consumption than the card it's replacing. And the high-pitched noise seems to have gotten a bit better.

      I'm aware that directx is really handled by wine. It's interesting, to me, that there are so many differences between behavior under opengl and behavior under directx. I don't think the translation layer is awesome.

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      • #4
        It also runs 20% less power, which is a big plus.

        Anyway, there doesn't seem to be much to do for useful settings -- the tips and setting advice seem to be based about nvidia use, not just the defaults. Still, it's livable. If it runs a while without crashing, it's probably a worthwhile change.

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        • #5
          Blizzard work on an 'WOW'style game based on OpenGL3+

          Blizzard understand 1 think about this...

          users use windowsXP and Linux and don't care abaut dx10 or 11...

          users wana play the same game on macos in openGL and linux in openGL and windows in openGL........

          i think if more companys's chance to openGL , microsoft come in big trouble.

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          • #6
            A followup on something I haven't figured out:

            My display is 60Hz.

            If I turn on antialiasing, there is a rock-solid frame cap of 30fps; I can get fewer, but not more, no matter what.

            If I turn off antialiasing completely, I can get up into the 40s or so.

            Note that I don't see any measurable difference between 2x and 8x antialiasing. Whatever the cap I'm hitting is, it's not pixel pushing.

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            • #7
              turn off vsync.

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              • #8
                I believe I did, but maybe I missed one of the places it can be set.

                What I don't understand, though, is why I'm being capped at HALF of the refresh rate by antialiasing. I could understand being capped at the refresh rate. I can't understand the cap being precisely half of the refresh rate.

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                • #9
                  Isn't that normal for vsync? If you can't push enough pixels for your hz, you get hz/2. And if not enough for that, hz/3. And so on.

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                  • #10
                    Originally posted by curaga View Post
                    Isn't that normal for vsync? If you can't push enough pixels for your hz, you get hz/2. And if not enough for that, hz/3. And so on.
                    Actually, no, it's not normal.

                    Because if I have vsync on, but no antialiasing, I get anywhere up to 47fps, because some frames make it under the wire and others don't.

                    I can get into a position where, without vsync, I can get well over 70fps (zoomed in a lot on a single polygon, basically). With vsync on, I get about 60. With any antialiasing, whether it's 2x or 4x, I get exactly 30.

                    But if I go someplace a bit more heavily loaded, with antialiasing on, I can get anything from 20 to 30, with all sorts of odd values inbetween, like 24.3, 23.1, and so on. It's just 30 that's a cap, and only with antialiasing on.

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                    • #11
                      Followup: Yes, indeedy, vsync was on in amdccle.

                      The behavior observed can be expanded, now:

                      vsync off, antialiasing 8x: Frame rates anywhere from 8-72fps.
                      vsync off, no antialiasing: Frame rates anywhere from 8-72fps. (No difference I can measure.)
                      vsync on, antialiasing 8x: Frame rates noticably lower, absolutely capped at precisely 30.
                      vsync on, no antialiasing: Frame rates noticably lower, seem to peak somewhere around 45.

                      Note that the frame rate I get with 8x antialiasing and vsync is not half of the frame rate with no vsync, and that rates are not in general even divisors of 60.

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                      • #12
                        Interesting followup:

                        No setting I make in amdcccle allows the in-game selection of vsync/not-vsync to affect results. However, if I set amdcccle to force vsync on or off, it seems to work.

                        On further study, I'm pretty sure that the frame rate issues here are wine/opengl/WoW -- it appears that WoW has a single primary worker thread that does ALL of the rendering, and that in practice it consumes at most a tiny fraction past a single core's time, which means that as the amount of geometry work for it to do increases, it slows down quite a bit. There does not appear to be an obvious way to fix this, short of massive reworking of the opengl libraries or something comparable.

                        So my best bet will be to hope that wine's directx translation improves, since apparently that engine is better in WoW.

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                        • #13
                          Hmm, two or three times today, crashed hard enough that there was no way I could find to recover except rebooting, and one where it needed a physical reset... That's not encouraging.

                          Is there any kind of temperature sensor or similar stuff I can use to figure out why it's being so crashy?

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                          • #14
                            aticonfig something. Can't remember the exact command, but just running aticonfig without any arguments dumps a list of valid arguments.

                            My guess is that you're just hitting driver bugs though.

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                            • #15
                              Have you tried playing wow in openGL? I know for at least wheni played wow with an ATI card in wine the performance was much much better through openGL.

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