Version: (using KDE 3.5.9) Installed from: Gentoo Packages Compiler: GCC 4.2.3 OS: Linux When lots of text is scrolling by in konsole, let's say during a software build performed on a remote machine via ssh, the load of my machine increases to a point were the system reacts sluggishly as long as the scrolling konsole tab is visible. If I change tab in the same konsole window, move another window in front of konsole or switch to another logical desktop the system load drops back to normal. Making the konsole window visible results in increased load again. Did some tests with other terminals (xterm, rxvt, xemacs), but this happens in konsole, only. The machine is a 3.2GHz P4 HT with i915 graphics chip.
> 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.
> 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) Looks to be X.org. > 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. Hmm, can't find where to change it in either program. > 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. Will try KDE4's konsole.
The main inefficiency (repainting the entire screen when scrolling) is fixed in KDE 4 and the change is too large to backport into KDE 3. If you are running a task which produces many lines of output rapidly then I suggest using a smaller window size.