Silicon on insulator (SOI) technology is an excellent choice for chip designs that require high performance and low power. IBM's SOI custom logic (ASIC) design system uses internal tools and flows in combination with solutions from a network of proven EDA vendors to support these high performance designs while managing the additional complexities introduced by the SOI process. The use of a qualified design system can add schedule predictability while simultaneously achieving high performance and power predictability.In this paper, we describe a high performance methodology for custom designs using a combination of Cadence, Synopsys, and IBM tools and flows. We discuss the benefits and challenges of the SOI technology and share results of high performance designs that were successfully manufactured using this methodology.Index Terms -very-large-scale integration, application specific integrated circuits, silicon on insulator, power, custom logic, design system.