It isn't obvious how long to run Blackbox when looking at a new data file. In general, it will need to run longer when there is more data and more attributes. However, it also depends greatly on the underlying relationships in the data which is usually the one thing you don't know when beginning. The 4of8.mbl file has some interesting relationships and takes a moderate amount of time to run. The semiconductor data is different. Once we give Blackbox a separate test set to check itself with, it only takes a short amount of time to find global linear regression (not much of a ``find''). We would probably run Blackbox for much longer, though, in hopes that it would turn up something better. It's usually best to set Blackbox running for a long time and then watch its results. When it appears to be making no more progress, hit 'q' to stop the searching.
Blackbox caches the results of its searches, so it can be restarted several times to continue a search it was doing. Its important to set the reset check box appropriately when doing this. When it is checked, all previous search results will be wiped out and the search begins from the current metacode. When it is unchecked, it keeps all previous search results and continues from there.