Steps to reproduce:

1. Create a Graph (Classic) widget for the CPU utilization:
   1. Check Show legend.
   2. Check Dynamic.
   3. Click Apply.
2. Resize the widget vertically to a minimum size.
3. Save the dashboard.

Result:

The chart3.php script, which is used for graph generation for dynamic hosts:

1. Is never finished until the PHP timeout.
2. Is being very CPU hungry.
3. The widget looks like this:

Expected:

The graph should be generated with minimum practical width and height, taking into account the legend, which was also selected to show.

The graph is ok to be cropped/clipped inside the widget.