Shared Memory Communication

Shared Memory Communication, SMC-R, is a new innovation on System z that improves performance for sharing data and reduces network overhead in data transmission. SMC-R introduces a new socket via RDMA communication protocol.  RDMA (Remote Direct Memory Access) is an industry standard that enables network adapters to transfer data using direct memory to memory communication, thereby eliminating networking stack overhead.

Workloads that are network intensive or transaction oriented will experience the greatest benefit.  For example, CICS to CICS workload using IPIC (IP interconnectivity) has seen up to 48% reduction in response time and 10% CPU savings in IBM benchmarks.  Other workloads that may benefit include WebSphere to DB2, WebSphere MQ for z/OS, or event FTP.

If you want more information, here's a link:
http://idcp.marist.edu/enterprisesystemseducation/95%20zTidBits%20SMC-R.pdf