Hi everyone!
This week I've been playing with DraftSight both on Linux and on Windows.
DraftSight is a Qt4 CAD drawing program that is very similar to AutoCad and it is available for free both for Windows and for Linux.

I used DraftSight for many months on Linux on my Core 2 Duo with 2gb of RAM computer and it is sluggish. Each time that I select a part of the drawing to modify an attribute there is a 5-10 second delay before the program unfreeze.

On my Windows-only laptop that I use mainly for running industrial automation software, I have installed DraftSight this week. This laptop is an old IBM ThinkPad A31p with a 1.7GHz Pentium 4 cpu and 512mb of RAM. It runs Windows XP. On this laptop, DraftSight runs perfectly well and there is no delay when I click on a part of a drawing, even if it is a much slower computer and the general performance of DraftSight is much better on Windows.

Is there a reason why I see such a big difference between this Qt4 program on Linux and on Windows? Does the difference is because of Qt4 or it could be because DraftSight has not been ported as well as it could be?

Qt3 has a very high performance and on a slow computer, it is even faster than GTK2. The UI element are drawn faster than almost every other GUI toolkits. Why does QT4 still suffer from these performance issues?

Have an happy spring break!
-Alexandre