[Qt-creator] optimization and file size between versions

[Duane]

I have Qt Creator version 2.7.2 and am using Qt 4.8.4.  My colleague has 
Qt Creator version 2.4.1 and is using Qt 4.8.1.  We are both running the 
Fedora 16.  We use the same project file and this project doesn't use 
the Qt libs.

The .pro file has
TEMPLATE = app
CONFIG += console
CONFIG -= qt


When he builds he gets an executable 1.5Mb.  When I build, I get an 
executable of 10.6Mb  Both are release builds.  We both use the same libs.

What can cause this?  How is optimization done here?  We build the same 
project for Windows in Visual Studio and the exe files are the same size 
but we've set the same optimization.