NetApp is moving towards 12Gbps SAS or SAS-3 connectivity for disk shelves. DS224C shelves with IOM12 (12Gbps SAS) modules have been available for a while and now new generation controllers have onboard 12Gbps SAS ports as well separate 12Gbps capable SAS adapters.
Older generation SAS 6Gbps ports use QSFP form factor connector while newer generation SAS 12Gbps ports use smaller Mini-SAS HD form factor connector (at least with NetApp gear). These form factors are not compatible, i.e you cannot cable QSFP connector to Mini-SAS HD port or vice-versa.
To make things more confusing, there are also 12Gbps capable ports that are using QSFP form factor connector. In case of NetApp, X2069-R6 adapter is example of such combination.