a b s t r a c tThis paper considers the extreme type-II Ginzburg-Landau equations, a nonlinear PDE model for describing the states of a wide range of superconductors. Based on properties of the Jacobian operator and an AMG strategy, a preconditioned Newton-Krylov method is constructed. After a finite-volume-type discretization, numerical experiments are done for representative two-and three-dimensional domains. Strong numerical evidence is provided that the number of Krylov iterations is independent of the dimension n of the solution space, yielding an overall solver complexity of OðnÞ.