Quartz 2D Extreme and Safari 3.1.1

Comments

• Reply 1 of 6

  pb Posts: 4,255member

  June 11, 2008 11:21AM

  Quote:
  

  Originally Posted by chinderland
  
  
  I just enabled Quartz 2D Extreme on my Powerbook G4 12" 1.33GHz Mac OS X 10.4.11. After reboot, I found that scrolling in Safari 3.1.1 became unresponsive and jumpy.
  
  
  
  However, whenever I visit a Web page with embedded video streams, such as a YouTube page, scrolling becomes smooth again thereafter (for all types of web pages).
  
  
  
  Anyone has similar experience on this?
  

  
  

  
  
  I have never played with Q2D Extreme but people have mixed and inconsistent experiences with it, mostly negative. There is a reason why it remained for so long at experimental stage and it is by default disabled.
• Reply 2 of 6

  chinderland Posts: 4member

  June 12, 2008 4:43AM

  Quote:
  

  Originally Posted by PB
  
  
  I have never played with Q2D Extreme but people have mixed and inconsistent experiences with it, mostly negative. There is a reason why it remained for so long at experimental stage and it is by default disabled.
  

  
  

  
  
  Thanks for replying my post.
  
  
  
  As far as I understand it, Quartz Extreme is graphics rendering through CPU + GPU. While Quartz 2D Extreme is about pushing most of the 2D rendering into the GPU. Basically, it is to provide hardware accelerated 2D drawing.
  
  
  
  Now both Quartz Extreme and Quartz 2D Extreme are enabled on my Powerbook G4. My questions is:
  
  
  
  1) How does Mac OS X Tiger choose between these two graphics subsystems? Does the system prefers one to the other?
  
  
  
  2) Why scrolling in Safari becomes smooth again, after I visit any web page with Video streams embedded?
  
  
  
  Can anyone give some technical explanations on these? Thanks.
  
  
  
  
  
  Powerbook G4 12" 1.33GHz 1.25GB Mac OS X 10.4.11
• Reply 3 of 6

  chinderland Posts: 4member

  June 13, 2008 8:14AM

  OK, I just disabled Auto Beam Synchronization. Now the scrolling in Safari appears to be smooth, even after reboot.
  
  
  
  Q2DE remains enabled. Hope this solved the issue ...
• Reply 4 of 6

  pb Posts: 4,255member

  June 13, 2008 9:00AM

  Quote:
  

  Originally Posted by chinderland
  
  
  OK, I just disabled Auto Beam Synchronization. Now the scrolling in Safari appears to be smooth, even after reboot.
  
  
  
  Q2DE remains enabled. Hope this solved the issue ...
  

  
  

  
  
  Probably for the special case you talk about. People that tried Q2DE say that it is generally problematic giving glitches here and here and not consistently delivering the performance gains Apple originally made us asssume. It has been apparently assessed as not appropriate yet for general use and that's why it is turned off.
• Reply 5 of 6

  mr. h Posts: 4,870member

  June 13, 2008 9:14AM

  Quote:
  

  Originally Posted by PB
  
  
  Probably for the special case you talk about. People that tried Q2DE say that it is generally problematic giving glitches here and here and not consistently delivering the performance gains Apple originally made us asssume. It has been apparently assessed as not appropriate yet for general use and that's why it is turned off.
  

  
  

  
  
  Quartz 2D Extreme was renamed Quartz GL with the release of Leopard.
  
  
  
  In Leopard it is enabled for some applications and disabled for others. In Tiger it's a system-wide all-or-nothing sort of a thing.
  
  
  
  Juicy info can be found at Ars Technicha:
  
  
  
  Quartz 2D Extreme.
  
  
  
  Quartz GL.
• Reply 6 of 6

  chinderland Posts: 4member

  June 13, 2008 1:34PM

  Quote:
  

  Originally Posted by Mr. H
  
  
  Quartz 2D Extreme was renamed Quartz GL with the release of Leopard.
  
  
  
  In Leopard it is enabled for some applications and disabled for others. In Tiger it's a system-wide all-or-nothing sort of a thing.
  
  
  
  Juicy info can be found at Ars Technicha:
  
  
  
  Quartz 2D Extreme.
  
  
  
  Quartz GL.
  

  
  

  
  
  Thanks for the links. I have read the Ars Technica article. On page 14 about Q2DE, the author wrote:
  
  
  
  "In Tiger, Apple provides one more big reason for developers to move away from QuickDraw. If an application uses QuickDraw to draw anything in a particular window, that window is entirely exempt from Quartz 2D Extreme acceleration. Instead, everything falls back to the Jaguar/Panther model: the CPU does the drawing and writes the results into a backing store in RAM."
  
  
  
  So, I suppose the video streams imbedded in web pages use QuickDraw? It makes sense that after I visit a web page with videos playing, the Safari window is exempt from Q2DE and uses Quartz Extreme instead, hence the scrolling becomes smooth again.
  
  
  
  Just a guess, though...