Testcomplete performance issue when scrolling in execution plan

I use TC on a virtual machine with 10 GB and quad-core processor. My test plan is 500 + tests items, grouped in by purpose in different virtual folders. Almost every time I need to find or change something in execution plan and come scrolling through it, UI of TC is frozen for 2-4 seconds for each iteration of mouse scrolling. Sometimes it's awfully annoying and time consuming.

Increasing virtual machine performance looks like most likely solution, but I would like to know your opinion and understand what is still missing.

Did someone encounter a similar situation? Are there any other technical recommendations for improving performance other than reducing number of tests items in plan?