Qt3 more fast than Qt4 ?

[commarmi]

Hello,

I created an application that draws 10000 lines in canvas, it allows to move the lines with the mouse.

Qt3 works well but Qt4 is slow.
I enabled Opengl with Qt4 but is more slow than whitout.

I attache a zip with 2 versions (qt3 and qt4).

is Qt3 more fast than Qt4 ?

Thanks