My landscape department is using ADT 3.3 but does not use the AEC objects so they are using AutoCAD and blocks. One of theri drawings is only about 1 meg in size but that particular drawing is very slow to respond when they select a block within the drawing. Their xref's are nothing out of the ordinary. Their hardware is fine otherwise they would have the problem with all drawings. Is there a variable I could change to speed this one up??