The GDSII file can be displayed using the assigned fill patterns or using only outlines for the data. Even though OpenGL acceleration is used, for large designs it is noticeably faster to display in outline mode.

Many IC designs use arrays to define repeated data. These arrays can take a long time to display as they must be “flattened” for the display engine.

Qckvu gives you three array display options - outline only, outer row and column and full array.