Problem with time processing and memory?

I simulated S-Parameter of many patch arrays using momentum than had a problem with time processing and memory. The process stopped because it was not enough memory (the memory is 1.5 G), If I reduced the mesh number, there was a warning which said my simulation would not be accurate.
Is there any solutions instead of reducing mesh?

Thanks for advance

Yes it is a solution. Change the computer with a better one.
Most of EM simulators have minimum resources requirements that should meet.