Horribly slow canvas redraw

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patdavid
2013-07-08
2014-10-01
  • patdavid
    patdavid
    2013-07-08

    Hi Simone,

    I've noticed that in both your build and Partha's builds, any canvas redraws are occurring horribly slow. Opening an image from my camera's native resolution (3000+ x 4000+), and then simply toggling the visibility of the layer off/on will take a long time.

    It appears to be working row by row to toggle the visibility, and it makes GIMP pretty much unusable. (The same problem happens if you try to apply levels/curves to a layer for instance).

    Here is a screen capture of the problem happening:
    http://www.youtube.com/watch?v=dxLlOJY7ZJs

     
  • asiga
    asiga
    2013-07-16

    I didn't see this happening on any 2.8 releases, on any of my systems (SnowLeopard and MountainLion). Given that it seems to be related to big images... did you properly configure Gimp for working with big images? I mean, did you go to Preferences>Environment and tune the cache size accordingly? I've it to 1GB (1024MB) on a 4GB machine, and I'd probably set it to higher value if I needed to work with larger images than I usually have.

     
  • I notice this as well and it is still the case in GIMP 2.8.10, OS X 10.7.5. I work with layers and large images a lot and it is very annoying. I have found no ways to make it faster.

    Tile cache is set to 2GB, I have 16GiB of RAM and a Core i7. This seems like something that is very poorly optimized. In GIMP 2.6, redrawing was much, much faster. Heck, our ancient PowerMac 8100/110 might have faster redrawn images of this size. There is no excuse for it being so slow in GIMP 2.8.

     
  • ... well, yes you're right. And sadly, there's nothing I can do for now in fixing it. As far as I know, 2.10 should redraw the canvas much faster.

    The only thing you can check, is to set the "number of processors" to 1 in GIMP's preferences. There's an issue with support for multiple processors. In 2.8.10, I've already hardcoded that to 1.

    Sorry, that I currently can't do anything about it

     
  • lavatyper
    lavatyper
    2014-03-20

    I am so glad that I found this thread
    I spent the last 2 years thinking that this type of behavior was normal.
    Then I asked a question on Answers Yahoo:
    https://answers.yahoo.com/question/index?qid=20140311152820AA2cjJR
    and I was basically told that it's not normal behavior and that it should be totally smooth.
    I set the number of processors to 1. It's still doing it (slow, block-style updating of the display that scan from left to right).
    I have GIMP 2.8.10. The previous posts are 3 months old and I don't see a newer version of GIMP available for download that would have remedied this problem.
    So, is this supposed to be normal??

     
    • It is not normal, in Linux it is a lot smoother. Since this seems to be an issue with GIMP's core and not the Mac build, we should probably file a bug at the main GIMP bugzilla: http://developer.gimp.org/bugs.html
      But it seems there is already a bug for this and it might be fixed in an upcoming build:
      https://bugzilla.gnome.org/show_bug.cgi?id=705645

       
      Last edit: Alexander Thomas 2014-04-16
      • lavatyper
        lavatyper
        2014-04-19

        How do I know what version of GIMP is the latest version posted on the Downloads page?
        I searched all over this page:
        http://www.gimp.org/downloads/
        and on the regular GIMP.org page, but I couldn't find the version number of the version of GIMP that is posted on the Downloads page.
        The only way for me to know is I have to keep downloading the version on the website, expand the installer package, then find out what version I downloaded and compare it with what I already have, then just to find out that I already have the latest version.

        So, since GIMP won't tell me what the latest version is on their website... can you just contact me letting me know when GIMP is updated so I can download it?
        Much appreciated.

         
      • lavatyper
        lavatyper
        2014-08-17

        Excuse me but can you reply to my post back on April 19th? I asked about when this update will be posted and never got a response.

        And why is it taking so long to fix this bug and post the update?

         
        • Excuse me but can you reply to my post back on April 19th? I asked about when this update will be posted and never got a response.

          And why is it taking so long to fix this bug and post the update?

          If you go to my site http://gimp.lisanet.de/Website/Download.html you can see the version of every package I’m offering.

          As far as I know, this bug will not be fixed in the 2.8 version but in 2.10.

          Why does it take so long? Well, there are only a few developers and GIMP is a very large project, so it may take a while. Are you willing to join?

           
  • stevereno30
    stevereno30
    2014-09-29

    http://www.youtube.com/watch?v=6se7xEcw0Hg

    As you can see from this video, I have the same problem with images that are much smaller. I can even see redraw when editing images smaller that 800x600! Is there any hope for 2.10? Or will the bug fixes you referenced earlier not be enough to make this frustrating lag disappear?

     
    • http://www.youtube.com/watch?v=6se7xEcw0Hg

      As you can see from this video, I have the same problem with images that are much smaller. I can even see redraw when editing images smaller that 800x600! Is there any hope for 2.10? Or will the bug fixes you referenced earlier not be enough to make this frustrating lag disappear?

      sorry, there's nothing I can do for now. That's one of the drawbacks of the native version. The Xquartz/ X11 version hadn't this issue. As I've written earlier, 2.10 should fix this somehow.

       
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    • Alex Kulesza
      Alex Kulesza
      2014-10-01

      Partha's experimental 2.9 build ( http://www.partha.com/ ) seems to have solved the slow redraw problem for me. It's considered unstable, so you may run into other problems, but at least it bodes well for future releases.

      (In my experience, all redraws are slow on 2.8.xx, it just becomes more obvious at larger image sizes.)