When LabVIEW updates an object with smooth updates off, it erases the contents of the object and draws the new value, which results in a noticeable flicker. Using smooth updates avoids the flicker that erasing and drawing causes. Right-click the graph and select Advanced»Smooth Updates from the shortcut menu to use an offscreen buffer to minimize the flicker. Using smooth updates can slow performance depending on the computer and video system you use.