On Tue, Jul 31, 2007 at 12:28:31PM +0200, Helge Hafting wrote: > Martin Vermeer wrote: > > ...and more importantly, you just confirmed my diagnosis of > > the problem. There is something in qt, or LyX's use of qt, > > that responds very badly to DRI both being turned on and > > practically unusable. > > > Clearly, qt4 think it is clever to use DRI for some things when it > is available. It is probably faster than "standard X" when hardware > is used for DRI, but much slower when the software fallback is used. > > A user with trouble can run "glxinfo". If one of the first lines > says "direct rendering: no", then software DRI is in use, and > commenting out DRI from the "Module" section in xorg.conf > will fix the performance problem.
Something like this was my suspicion. > The long-term fix is to report the bug to qt developers. > The information "glxinfo" displays is available to qt too, > through standard DRI operations. They should not blindly > use DRI if available - only if "direct rendering" is hw accelerated. > Otherwise it is not a win. Is a workaround possible for LyX? This should be in the release notes. > I have reported this qt4 bug through the debian bug report > system - lets hope they fix it as the fix is a simple one. > > > Helge Hafting - Martin
