Hi all,

I have 2 widgets, both have the size 300x300 pixels. Each widgets have their own QTimer set periodically to fire every 20ms. In the timeout() slots, I make some small calculations and call update(). In the method paintEvent() I paint a QPixmap.

The timer of the second object is started 1 second after the first objects timer is started.

Here is the pseudo code of timeout slot and paint event:

void timeout()
{
print_time();
do_some_calc();
update();
}
void paintEvent(.....)
{
print_time();
QPainter painter(this);
painter.drawPixmap(0,0,myPixmap);
print_time();
}


When I start the first timer, the timer slot is called about every ~40ms. When even the object starts its timer, the timers get fired about every ~80 ms.
The paintEvent consumes about 5-7 ms.
When I comment out the update() calls in the timeout slots, the timers get fired about 21-22 ms.

My question is, why I get such a bad resolution and any advice to workaround this?

My system runs under PPC, Linux 3.1.4 and Qt 4.7.4. The behaviour is under both framebuffer und DirectFB the same.