Walter Alef - "Software vs. hardware Correlators for VLBI"
In the last few years the performance price ratio of commodity computers has increased continuously by about a factor of two per about two years. It has now become economical to use general purpose comput clusters and software correlators for small continental to large global VLBI networks. While the development of hardware correlators costs millions and typically takes several years, software correlators can be developed rapidly at low cost. They can be adapted to new needs and techniques quite easily and offer themselves in a very straightforward way to new developments like (near real-time) e-VLBI.
Walter Alef, vice chairman of NA4 "Engineering Forum", chairman of the EVN-TOG, walef@mpifr-bonn.mpg.de