This video introduces Flownex’s non-iterative transient solver, a major performance enhancement designed to significantly reduce transient simulation run times. Unlike the traditional iterative solver, which requires convergence calculations at every time step, the non-iterative solver solves the same underlying physics without performing iterative processes at each step, making it especially effective for simulations with small time steps and complex control studies. Users can easily switch between iterative and non-iterative modes before or during a transient simulation through the solver settings or a convenient ribbon toggle. Using an RS-25 rocket engine model as an example, the demonstration shows how the non-iterative solver dramatically improves performance, reducing solve times from approximately 1.5 seconds per time step to around 0.25–0.3 seconds per time step. This capability enables engineers to simulate large, highly interconnected systems more efficiently while maintaining the same physical accuracy as the traditional solver.