A prediction logic device operating in conjunction with a vector processor to predict, before the completion of the translation of the virtual addresses of all of the data elements of a vector, the valid performance of all virtual-address to physical-address translations for the data elements of the vector. The prediction logic device asserts an MMOK signal to a scalar processor when it becomes known that no memory management fault and/or translation buffer miss will occur such that the scalar processor can resume vector instruction issue to the vector processor at the earliest possible time.