1. A method comprising: responsive to detecting a read request referencing a specific memory address from a first entity that misses in a core cache of the first entity: sending an order-marker corresponding to the read request to the first entity on a first channel; sending a fill corresponding to the read request to the first entity on a second channel; and responsive to detecting an update request, ordered after the read request, referencing a specific memory address: sending update data packets on the first channel to all non-last accessor entities having copies of the specific memory address; sending a probe update data packet on the first channel if the last accessor entity is different than the second entity; and sending an update acknowledgement (upd_ack) to the second entity.