Hello
Just curious here.
What sort of structure are you simulating that requires so much memory?
I have simulated 12 layer LTCC pcb without much of a problem.
I assume either you have a very large layout of a very intricate/complex layout.
If so, I have the following suggestions for you.
1. Be sure that you have the most simplified mesh.
2. Convert circles to simple rectangles.
3. Try using RF instead of Microwave mode.
4. Try disabling thick conductor expansion.
Hope this was useful.
Aswin