I take it data are not sent continuously.
Then, this means that sudden loss of performance is unexplained.
It usually happens when I open a new file in a new tab.
Today, it happened even if I closed the old file to open a new one.
Loss of performance = everything lags. Lagged drag and drop, takes noticeably longer to create a new item on the screen, etc.
Current solution is: you have to restart the program to make it run smoothly.
I take my issue to be similar (if not identical) to this one: http://yed.yworks.com/support/qa/1278/performance-cpu-memory-usage?show=6603#c6603