A processing platform is configured to communicate over a network with one or more client devices, and to receive a request from a given one of the client devices for a proposed configuration of a storage system. The processing platform identifies based at least in part on the received request at least one processor to be utilized in implementing the storage system, selects a particular one of a plurality of storage system performance models based at least in part on the identified processor, computes a performance metric for the storage system utilizing the selected storage system performance model and one or more characteristics of the identified processor, generates presentation output comprising: (i) the performance metric, and (ii) information characterizing at least a portion of the proposed configuration of the storage system, and delivers the presentation output to the given client device over the network.