Technologies for efficient synchronous replication across heterogeneous storage nodes can provide the performance of high-speed storage units while leveraging low-cost and high-capacity backup storage units within the same system. The performance of low-cost, high-capacity hard disks may be improved by initially storing data into sequential physical locations. A sequential journal of I/Os may be used in a replicated secondary node to allow for rapid completion of I/Os. A separate background process can later scatter the sequentially logged I/O data into its proper location for storage. A programmable n-way router can be configured to route I/Os as needed to improve overall performance of the storage unit. A secondary node log device can also be used to provide continuous data protection (CDP). Lastly, packetizing together I/Os prior to delivery to a secondary node may reduce interrupts and context switches in the primary node, thereby improving performance of the storage system.