KDE SC 4.5.0 has some problems with some video cards including mine. Upon Release Arch recommended several workarounds. One of which wasexport LIBGL_ALWAYS_INDIRECT=1 before starting KDEI decided that it was the easiest, best method. But I don't know what it does or how it impacts my system. Is it slower than the default? should I remember to keep an eye on the problem and disable it later once it's fixed?
What does LIBGL_ALWAYS_INDIRECT=1 actually do?
xorg;kde;opengl
Indirect rendering means that the GLX protocol will be used to transmit OpenGL commands and the X.org will do the real drawing.Direct rendering means that application can access hardware directly without communication with X.org first via mesa.The direct rendering is faster as it does not require change of context into X.org process. Clarification: In both cases the rendering is done by GPU (or technically - may be done by GPU). However in indirect rendering the process looks like:Program calls a command(s)Command(s) is/are sent to X.org by GLX protocolX.org calls hardware (i.e. GPU) to draw In direct renderingProgram calls a command(s)Command(s) is/are sent to GPUPlease note that because OpenGL was designed in such way that may operate over network the indirect rendering is faster then would be naive implementation of architecture i.e. allows to send a buch of commands in one go. However there is some overhead in terms of CPU time spent for context switches and handling protocol.