the replot of a qwtPlot is too slow

Hi There,
I'm Using Qwt 6.0.1 and Qt 4.8.0.

I have a QwtPlot and attach on it one qwtPlotCurve with 100000 points and a qwtPlotItems.
I want to redraw the qwtPlotItems based on mouse movement. After updating of the qwtPlotItems position is necessary make a replot the qwtPlot to show the new qwtPlotItems position.
For each mouse movement the entire qwtPlot is redraw therefore this passage is very slow, consequently the movement of the qwtPlotItems results not-allingned with the mouse movement. In short terms the updating of User Inteface isn't coherent with mouse movements.

Is there a way to make more efficient this operation? For example is there a way for not redraws the entire qwtPlot, as in case of replot operation.