QT version 4.8.2
I have created two QListWidget objects that shall contain the Output from the data processing and the Debug issues found while processing the data. As a message is received by the ui thread it is added to the respective ListWidget (via addItem) the message can be as small as a single line of information (summary view and debug ListWidget) to couple hundred lines within a single message (verbose mode). As the number (count) of items increases so does the CPU utilization to a point that a programmatic threshold is achieved whereby the slowdown issues more debug messages which creates more messages (loop). So to attempt to restrict this from happening I have throttled the count to a low number by removing the zero index item in the list. I can live with it, but it is not ideal.

My question is such... Why is CPU utilization increasing as more items are being added to List? I would understand memory usage to increase. Currently I run at ~20% with GUI, ~7% if built without QT. If I increase the size (max item count) of the ListWidgets to 500 items, as I would like, the CPU jumps to ~70% as the limit approaches. It does not matter whether summary mode or verbose the CPU increases, verbose just gets there faster.