转载：QT4 apps slooooow in ssh

如果QT4使用默认的“-graphicssystem raster”的话，通过SSH转发X会话时，QT4做的程序会占用巨量带宽，导致程序狠卡。这种情况应当使用native的graphicssystem。

http://comments.gmane.org/gmane.linux.redhat.fedora.general/413587

亮点：

The default is the "raster" graphics engine, which works somewhat like

you described in your original e-mail:

http://labs.qt.nokia.com/2009/12/18/qt-graphics-and-performance-the-raster-engine/

The "native" graphics engine uses regular X11, which will probably

always be best over SSH.

Qt also respects the QT_GRAPHICSSYSTEM environment variable to

configure this, so you can add `export QT_GRAPHICSSYSTEM=native` to

your ~/.profile or wherever to make it your "default".