The new plasma control system of the HBT-EP Tokamak utilizes a graphical processing unit (GPU) to magnetically control the 3D perturbed equilibrium of the plasma. The system achieves cycle times and I/O latencies below 5 and 10~$\mu$s respectively and handles up to 96 inputs and 64 outputs. The control algorithms are massively parallel and run on the 448 cores of a Tesla GPU. A new architecture uses peer-to-peer PCIe connections to transfer data directly between GPU memory and AD/DA modules without using host RAM or CPU. The Linux host system does not require any real-time extensions.
