 The more complex instructions also add to the complexity of the decoders, which might slow down the decoding of the more common instructions such as normal adding.In fact, vector processors work best only when there are large amounts of data to be worked on.For this reason, these sorts of CPUs were found primarily in supercomputers, as the supercomputers themselves were, in general, found in places such as weather prediction centers and physics labs, where huge amounts of data are "crunched".