Large-scale problems involving geometric data arise in numerous settings, and severe communication bottlenecks can arise in solving them. Work is needed in the development of I/O-efficient algorithms, as well as those that effectively utilize hierarchical memory. In order for new algorithms to be implemented efficiently in practice, the machines they run on must support fundamental external-memory operations. We discuss several advantages offered by TPIE (Transparent Parallel I/O Programming Environment) to enable I/O-efficient implementations. Categories and Subject Descriptors: D.4.2 [Operating Systems]: Storage Management - Secondary Storage; D.4.4 [Operating Systems]: Communications Management - Input/Output; E.2 [Data Storage Representations]: Contiguous representations; F.2.2 [Analysis of Algorithms and Problem Complexity: Nonnumerical Algorithms and Problems - Computations on discrete structures, geometrical problems and computations; B.4.4 [Input/Output and Data Communications: Performance Analysis and Design Aids] - Formal models, Worst-case analysis;
General Terms: Algorithms, Design, Languages, Performance, Theory. Additional Key Words and Phrases: computational geometry, I/O, external memory, secondary memory, communication, disk drive, parallel disks.