Dear Allin and Jack, I'have observed some increased efficiency in the built-in multi-core support during the last few months. Just out of curiosity: has really anything changed in this direction or is it simply my subjective impression that the CPU usage has substantially increased running the same script on the same machine? For instance, on a modern i5 4-core machine almost 2 cores are automatically exploited for heavy-loop and heavy-matrix computations. On an older AMD 2-core machine the CPU usage is slightly lower but still the 2nd core is at least used up to 40% or so. Thanks, Artur