Apparatus and method for maintaining real-time coherency between a local cache of a target device and a client cache of a source device during execution of a distributed computational function. In some embodiments, a source device, such as a host computer, is coupled via a network interface to a target device, such as a data storage device. A storage compute function (SCF) command is transferred from the source device to the target device. A local cache of the target device accumulates output data during the execution of an associated SCF over an execution time interval. Real-time coherency is maintained between the contents of the local cache and a client cache of the source device, so that the client cache retains continuously updated copies of the contents of the local cache during execution of the SCF. The coherency can be carried out on a time-based granularity or an operational granularity.