Soap UI NG when I have to map large APIs I am having performance issues after about 10-12 fields?

We have Ready API - I go into the Soap UI NG area to work on a project.

I have really large APIs that load customer's data.

If I have to map more than 10-12 fields Ready starts to bog down and I have to save/close and restart or the application will completely lock up.

When I look at task manager my CPU is pegged and the fan starts running on my laptop.

I restart - get another 10-12 fields mapped and the cycle starts again.

Is anyone else reporting performance issues when mapping large API's