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QT Creator slow performance on ubuntu

  • Hi,

    I wonder what is the cause to slow QT Creator performance on files with more than 1000 line of code on ubuntu ? I have deactivated all effects (not even anti aliasing). Note that, I am having this issue with both 2.0 and 2.1 version of QT Creator. Slowliness comes also from intellisence and seems related to the code edit window.

    Any idea on how to improve that ?


  • Creator is really snappy for me on Ubuntu...

    For code completion we need to take in account all the code that is in your file. This includes all the headers you use (and those that are included by those, etc.). So what are you including? Can you trim down the number of include statements or use less generic headers (like QtGui/QWidget instead of QtGui)? If that is an option then compile times would also decrease a lot:-)

  • Hmm, for me it is not the case now, but it is still my favourite. However the performance problem seems to happen when I press the enter key and it needs to create a new line: it would become very slugish when a file exceeds 500 lines of code (I don't have a lot of includes: common iostream, vector, string and map). Maybe it is the rendering that is bad and something is wrong with QT 4.7. Please note that I am using a very simple theme with no compositing and metacity.

    My system is:

    Intel Core2 Duo 2GHz, 2Gb RAM
    Nvidia 8400G 128M RAM and 260.19.06 driver.

    So can you please tell me how to make QT Creator usuable again ?


  • What version of Qt is that? If that's 4.7.0 try 4.7.1.

  • I'm using the Qt Creator on a Ubuntu virtual machine and it is not slow at all! I'm using the Qt SDK that means Qt 4.7.0 but the Qt Creator RC!

  • I am using QT 4.7; I have tried QT Creator 2.1 RC, seems to be a little better but not noticeably better!

    Are there any performance enhancement with QT 4.7.1 ?

  • I have used Qt creator on ubuntu 9 and did not notice any problems.

  • farakon: Please update to Qt 4.7.1. There are known performance issues with Qt 4.7 (see the release notes).

  • To those having the same problem, I restart QT creator with:

    qtcreator -graphicssystem raster

    QT creator becomes as responsive as it was before. So hope it helps.

    I wonder why the raster is faster than the native system, I have read the blog, so the question why not make it by default ?

  • Thanks @farakon, it's just that i needed. QtCreator was very slow when i moved the cursor with the keyboard, it leave a "shadow". Now it run fine.

  • Thanks @farakon as well. I was having the same problem (text cursor not very responsive) and it was solved with the -graphicssystem raster switch.

  • i am also using qt on ubuntu 10.10 , it works complitely fine on my laptop.

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