The Genesis benchmark suite has been assembled to evaluate the performance of distributed-memory MIMD systems. The problems selected all have a scientific origin (mostly from physics or theoretical chemistry), and range from synthetic code fragments designed to measure the basic hardware properties of the computer (especially communication and synchronisation overheads), through commonly used library subroutines, to full application codes. This is the second of a series of papers on the Genesis distributed-memory benchmarks, which were developed under the European ESPRIT research program. Results are presented for the SUPRENUM and iPSC/860 computers when running the following benchmarks: COMMS1 (communications), TRANS1 (matrix transpose), FFT1 (fast Fourier transform) and QCD2 (conjugate gradient kernel). The theoretical predictions are compared with, or fitted to, the measured results, and then used to predict (with due caution) how the performance might scale for larger problems and more processors than were actually available during the benchmarking.