Hi Rudy, thanks for posting the file for me to test.

It looks like MoI is creating an excessively large display mesh for this surface. One thing that will help with it is if you go to Options and uncheck "Add detail to inflections".

But even with that turned off, memory usage will spike up to 600 megs for a moment before it settles back down again. If you have less than 1GB of memory on your machine this will be a problem. You can also change 2 additional settings to reduce the memory consumption - set the "Surface angle" and "Trim curve angle" in the options dialog to 20 instead of the default 10. This will make a coarser display mesh which pretty much solves the problem that is happening in this particular case.

Later on when you are done working with this large surface you will probably want to turn these settings back to the default so regular objects look nice and smooth instead of more jaggedy.

I should be able to tune this up so that it works better and doesn't hog so much memory for larger single surfaces like this.

Thanks for reporting the problem!

- Michael