Technologies for demoting cache lines to a shared cache include a compute device with at least one processor having multiple cores, a cache memory with a core-local cache and a shared cache, and a cache line demote device. A processor core of a processor of the compute device is configured to retrieve at least a portion of data of a received network packet and move the data into one or more core-local cache lines of the core-local cache. The processor core is further configured to perform a processing operation on the data and transmit a cache line demotion command to the cache line demote device subsequent to having completed the processing operation. The cache line demote device is configured to perform a cache line demotion operation to demote the data from the core-local cache lines to shared cache lines of the shared cache. Other embodiments are described herein.