One disclosed embodiment is a multi-processor system comprising a processor having a processor pipeline that executes program instructions with data from a speculative fill that is provided in response to a source request. The multi-processor system can further comprise a non-retired store cache that retains non-retired store data based on program instructions to store data into a data cache associated with the processor. The non-retired store data can be written to the data cache if data of a speculative fill associated with the non-retired store data is determined to be coherent. Other apparatus and methodologies are disclosed.