Le mercredi 28 juillet 2010 18:46:16, Russell Brown a écrit : > There's something in the way KDE4 is using the GLX/Compositing stuff > that blows away LTSP clients :-(
AFAIK the problem is merely in Qt graphical backends and X11. See the links at top of this page (Qt emplooyee blog): http://labs.trolltech.com/blogs/2010/01/21/qt-graphics-and-performance- generating-content-in-threads/ And on Zack Rusin's blog: http://zrusin.blogspot.com/2009/08/2d-in-kde.html For french readers http://linuxfr.org/~steckdenis/29318.html I tried to resume the situation below. May be its too aproximated, but at least it is short. Please note that I'm not at all a specialist, I've just read some web pages: Qt use different backends for each OS. Under Linux, Qt can mainly use X11 (XRender) and OpenGL. Default is X11 (XRender), the rendering is done by the graphical card, but it is very slow in drawing little things (like controls with themes). The OpenGL backend is still slow (need good graphical drivers), and not complete. There is another one: Raster, which is fast and stable. The rendering is strictly done on the CPU (default on Windows). The drawback is that it use a lot of bandwidth (unusable with ltsp). And that you need to recompile Qt to use it on all your apps by default. Note that you can try the various backend by passing options to applications -graphicssystem=native (means X11 on Linux) -graphicssystem=raster -graphicssystem=opengl Also, things got better by choosing very simple graphicals themes and styles. Sadly, native Qt's MS Windows 9x is one of the simplest ; someone reported me that Cleanlooks style is fast on network too. Backends rendering is a general problem on systems with X11. It is just more visible on KDE4 because of their innovative things (plasma, everything themable, ...) and because of Qt. KDE rendering is fast on Win. But things evolve. The OpenGL backend is expected to be more and more better and faster. Hope this help regards Xavier [email protected] - 09 54 06 16 26 ------------------------------------------------------------------------------ The Palm PDK Hot Apps Program offers developers who use the Plug-In Development Kit to bring their C/C++ apps to Palm for a share of $1 Million in cash or HP Products. Visit us here for more details: http://p.sf.net/sfu/dev2dev-palm _____________________________________________________________________ Ltsp-discuss mailing list. To un-subscribe, or change prefs, goto: https://lists.sourceforge.net/lists/listinfo/ltsp-discuss For additional LTSP help, try #ltsp channel on irc.freenode.net
