With the recent agreement to build the multi-billion dollar international burning plasma experiment known as ITER, fusion simulations will be growing dramatically in both complexity and size. The Gyrokinetic Toroidal Code (GTC) is a 3D Particle-In-Cell code used for studying the impact of fine-scale plasma turbulence on energy and particle confinement in the core of tokamak fusion reactors. To tackle global ITER-size simulations with full kinetic ion and electron physics, GTC will require new algorithms and supercomputers will have to grow in capabilities. We will review recent code modifications made to prepare for these new, exciting simulations and examine the performance of GTC on both the Cray XT3 and Cray XT4 systems using the latest Cray tools. Finally, we will look to the future and discuss plans for GTC and how that will effect its performance on future computers.