Thank you all for your answers. They've been very helpful in understanding the problem. I understand that refreshing the screen is hard and I know that LV requires a lot of resources but still - we're talking about 10 FPS - that's not a fast refresh rate. In response to Shea's question, we have a few programs in which such constructions exist. Bad programming practices? Maybe, but I still think a modern computer should be able to handle this task. Anyway, from now on I'll try to avoid doing it, if possible. P.S. Shea - I understand what you're saying about local variables, but I'd still expect most programs to have quite a few of them. Thanks again for your answers.
