I am creating a multiple-loop (4) process control VI that passes 2 basic types of data between loops, i.e., an integer array and clusters. Originally queues were used to transfer the data, but I ran into problems when trying to dequeue more than one queue per loop. I next tried functional globals, but were just too slow to prevent the empty queue syndrome. Next came global variables, which proved to be the fastest, contradicting all conventional programming practices. All this experimentation was done on a single-core PC. I now have implemented the code on a multiple-core (4) PC. Does the use of global variables relagate the mutliple-core architecture to single-core execution? Perfmon indicate 25% CPU usage, don't know if this is one processor doing 100%, or 4 x 6%? I have seen a global queue used to transfer data, which sounds like an oxymoron, but could this be a good way to go?