Magnetron performance is ultimately the determining factor in the productivity of glass sputter coating technology. Maximum power density, target utilization and efficiency, coating uniformity, material deposition rates, vacuum reliability, arc and debris control, quick turnaround and ease of maintenance all contribute to the overall efficiency of any magnetron sputter source. The state of the art in magnetron sputter deposition is now based upon reactive sputtering of rotatable cylindrical magnetrons using AC power supplies. A new generation of rotatable sputter magnetrons is based upon design from first principles for optimized use with high current mid-frequency AC sputtering power supplies. Improved target designs result in more robust vacuum sealing and greater than 90% material utilization. Improved magnet fixtures and process control results in stable, high deposition rates for reactive sputtering with 3% uniformity range. Results from lifetime testing and production systems are presented. Critical performance features including current handling capability, seal lifetime, and process uniformity are discussed. (c) 2005 Elsevier B.V. All rights reserved.