With 8GB RAM, **AMPERES** can solve very large models with non-linear materials. However, the solution time depends on the memory requirements for solving the model in AMPERES.

Before starting to solve the model, you can find out whether the model yields a fast solution or not. After assigning the surface elements to the model, select the the **“Problem Size”** command of the “2D Quadrilateral Elements” or “2D Triangular Elements” menu to check the memory requirements to solve the model.

Upon selection of the **“Problem Size”** command, AMPERES writes the memory requirements in the dialog area. Suppose, for a typical model, the message written in the dialog area of the program is “Scratch File #1 needs 234 Mbytes; Scratch File #2 needs 123 Mbytes” (please note that the size of the Scratch File #2 is always smaller than that of the Scratch File #1 for any model).

For every model, the Scratch File #1 is written to the hard disk while the model is being solved. Whereas the Scratch File #2 is held in the RAM if it fits into the RAM available on the machine.

If the available RAM is not sufficient for the Scratch File #2, it is also written onto the hard disk. Since the Scratch File #2 is accessed many times while the model is being solved, **AMPERES** obtains the solution quickly when the Scratch File #2 fits into the available RAM. If Scratch File #2 does not fit into the RAM available, **AMPERES** has to read Scratch File #2 from the hard disk many times while solving the model. Hence, the solution will take more time.