Here is some related information on the resolution of QTimer.
QTimer
's resolution is about 15 ms or so on Windows.
I believe it uses something similar to GetTickCount()
.
http://msdn.microsoft.com/en-us/library/windows/desktop/ms724408(v=vs.85).aspx
The resolution of the GetTickCount function is limited to the resolution of the system timer, which is typically in the range of 10 milliseconds to 16 milliseconds.
http://qt-project.org/doc/qt-4.8/qtimer.html#accuracy-and-timer-resolution
Timers will never time out earlier than the specified timeout value and they are not guaranteed to time out at the exact value specified. In many situations, they may time out late by a period of time that depends on the accuracy of the system timers.
The accuracy of timers depends on the underlying operating system and hardware. Most platforms support a resolution of 1 millisecond, though the accuracy of the timer will not equal this resolution in many real-world situations.
If Qt is unable to deliver the requested number of timer clicks, it will silently discard some.