> My general understanding is that Linux has become something of a
> second-class citizen with Qt4/Qt5; rather than optimising the graphics
> code for X11 as Qt3 did, it uses the CPU to draw all elements, then only
> uses the graphics card for certain 3D operations and transformations.
> While I don't have all the links handy right now, a quick Google search
> turned up these related links:
> https://bugreports.qt-project.org/browse/QTBUG-19636?focusedCommentId=177704#comment-177704
> http://phoronix.com/forums/showthread.php?73736-Qt5-s-Linux-Requirements-Cause-Problems/page3
>
> This may change in Qt5, but would then rely heavily on powerful, non-free
> graphics hardware to function (scenegraph backend). As another ancdotal
> datapoint, I have noticed that Qt4-based applications have always been
> significantly slower than equivalent Qt3 applications. Note that
> "equivalent" in this case means displaying a similar number of on-screen
> widgets; many Qt4 applications have had so much functionality stripped out
> and/or hidden behind a bulky "touch" interface that direct comparisons are
> quite difficult.
Yes, it is true. You can even compare it with programs that haven't changed at all since KDE3 like KPPP and Ark. The performance is worse on Qt4.

>
> Between the noted performance problems and the fact that the Qt project
> seems to be completely unable to resolve several bug reports related to
> incorrect graphics primitive drawing (for example,
> https://bugreports.qt-project.org/browse/QTBUG-25896), it would appear
> that the TDE project's decision to stick with Qt3 was the correct
> decision.
>
> Tim
Yes, I 100% agree that the decision to stay with Qt3 is the right one! The performance of Qt3 is a big part of the reason why I prefer TDE over KDE. It is amazing to see everything appear just as soon as you click on it!

Thank you for your hard work on TDE!
-Alexandre