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
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
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... http://phoronix.com/forums/showthread.php?73736-Qt5-s-Linux-Requirements-Cau...
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.
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
On Saturday 09 March 2013 01.36:40 Timothy Pearson wrote: (...)
My general understanding is that Linux has become something of a second-class citizen with Qt4/Qt5;
(...)
Not surprising as long as it was a Nokia business. Any hope that Digia does better? (Wikipedia writes: "About 125 Qt developers were transferred to Digia, with the immediate goal of bringing Qt support to Android, iOS and Windows 8 platforms, and to continue focusing on desktop and embedded development.". I doubt you can get any performance on an Android device if the processor has to do all the work.
Thierry
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... http://phoronix.com/forums/showthread.php?73736-Qt5-s-Linux-Requirements-Cau...
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
Hi Guys,
On Saturday 09 March 2013 00:16:01 Alexandre Couture wrote:
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.
Like you I use DraftSight on PCLoS.
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.
I find the same problems ! Maybe not quite as severe but certainly the graphics performance leaves something to be desired. I'm currently running a dual core 3Gig P4 with 1Gb ram.
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.
On my laptop, a 1300Mhz 1Gb running Open SuSE 11.1, DraftSight runs a lot more smoothly without the jerky mouse and refresh delays.
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?
?? That could be a question for the DS developers.
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
-
Alexandre Couture -
Baron -
Thierry de Coulon -
Timothy Pearson