Qckvu has several options that can significantly speed up the display - these become more and more effective as the GDSII file size increases. The principle behind all of these speed ups is to display only “important” data and to filter out unimportant data.

The display filter works by determining how large an entity will appear on screen and then removing it if it is less than the pixel threshold set by the user. Notice the display difference with different threshold settings. (0 passes everything.)

As you zoom in, entities require more pixel space and thus pass the filter. However, when zoomed in there are less entities in the display window to process.

GDSII files are hierarchical; there can be 5, 10 or even 20 levels of hierarchy in a large IC design.

When first browsing a large design it is not always necessary to see what is going on 10 levels down. Instead, set the nesting level to 2 and you will see entities in the top level and one level below. This is generally enough to get the lay of the land and requires the viewer to display many less entities.

At left you can see the results of different values of nesting on a small IC.