4 Replies Latest reply: Oct 22, 2008 10:42 AM by (Maasel_Sull) RSS

    Some GPU questions

    klsteven-vBdprK Community Member
      There are some questions I have about screen redraw in CS4.
      First off screen redraw without GPU acceleration is much slower than in CS3.
      In the "advanced options" of the GPU settings there is the option "color matching".
      If I turn it off I don`t have the option to softproof anymore. That is turning softproof on or off doesn`t change the colors anymore.
      If I turn it on, I can softproof again but I get banding in a black to white gradient. Slight, but noticable. To see the diffenrence that the settings make you have to close and open the document again.
      Just saw that "color matching" seems to turn off the whole colormanagement.
      Colors are not displayed correct anmore but look like in a browser.
      So do I have the choice between colormanaged pictures with slight banding or non colormanaged pictures without banding?
      BTW. I don`t see that banding in CS3.

      Vista 32bit Geforce 8600 GT/512MB, newest driver
        • 1. Re: Some GPU questions
          Mylenium CommunityMVP
          Mmh, might be a limitation in the implementation of OpenGL. In theory you should see no artifacts at all on your card. Color Matching enables an extra processing step which is required for non-sRGB images, so you cannot really go without it if you use hardware accel. I'm just not sure how it all goes together, as I'm a video-centric user and usually forego any of that color profile stuff. Maybe someone more qualified can provide some better info to you.

          Mylenium
          • 2. Re: Some GPU questions
            klsteven-vBdprK Community Member
            Now I made a black/white-gradient in ProPhoto RGB. Wow, this is really ugly.
            Banding and red/green shifts within that banding if "color matching" is on. But without "color matching" there`s no colormanagement at all.
            Looking at that same file in CS3 everything is fine!
            • 3. Re: Some GPU questions
              klsteven-vBdprK Community Member
              Can anyone replicate this behaviour?
              Just make a B/w gradient in ProPhoto RGB and see if you get banding.Then turn off "color matching" (in Open GL`s advanced settings) and test again. Then test again without Open GL.
              • 4. Re: Some GPU questions
                Funny bug in CS4, when I enable OpenGL I cannot see picture. Its grey frame. Picture shows up only when I moving it.

                Vista 32bit Geforce 8600 GT/512MB, newest driver