  In this paper I describe some results on the use of virtual processors
technology for parallelize some SPMD computational programs. The tested
technology is the INTEL Hyper Threading on real processors, and the programs
are MATLAB scripts for floating points computation. The conclusions of the work
concern on the utility and limits of the used approach. The main result is that
using virtual processors is a good technique for improving parallel programs
not only for memory-based computations, but in the case of massive disk-storage
operations too.
