...However, a direct solver may enhance performance. Consider specifying the use of a direct solver.

An iterative solver was used to obtain the solution; however, a large number of iterations were needed in order to get a converged answer.

By default, the program will either choose a direct or iterative solver based on analysis type and geometric properties. (In general, thin models perform better with a direct solver while bulky models perform better with an iterative solver.) However, sometimes the iterative solver is chosen when the direct solver would have performed better. In such cases, you may want to force the use of the direct solver. You may specify the solver type in the Details view of the Analysis Settings folder.