[Konsole-devel] [Bug 158844] Machine load increases when much text is scrolling through konsole, system reacts slowly

[Robert Knight]

------- You are receiving this mail because: -------
You are the assignee for the bug, or are watching the assignee.
         
http://bugs.kde.org/show_bug.cgi?id=158844         




------- Additional Comments From robertknight gmail com  2008-03-06 17:16 -------
> he load of my machine increases to a point were the
> system reacts sluggishly as long as the scrolling konsole tab is visible.

Is this load happening inside Konsole or inside X.org?  (in other words, when viewing processor usage using a tool such as ksysguard, is X.org using the CPU or is Konsole)

> Did some tests with other terminals (xterm, rxvt, xemacs),
> but this happens in konsole, only. 

By default xterm uses a simpler non-antialiased font which is somewhat quicker to draw than Konsole's antialiased fonts.  You can turn anti-aliasing on in xterm, or off in Konsole to get a more equal footing.  

If you want to get better performance in Konsole, there are a number of things you can do:

- Use a plain, opaque background (No transparency, no image effects)
- Turn off anti-aliasing

Every time the screen scrolls Konsole repaints the whole window in KDE 3.5.  Scrolling the screen is somewhat faster, especially with large windows, in KDE 4 where Konsole tries to only draw newly exposed lines.

The cost of scrolling depends mostly on the window size.  If you have a large window (eg. 1000x1000+) then there will be a perceptible performance impact, at least under KDE 3.