I believe Compellent is currently using SNMP v2C. That was added in SCOS 6.3. I did not see anything in the 6.4 new features or 6.5 release notes documents that I have on adding v3. 
Hi guys  Does Compellent support SNMP v3? In our network, only SNMP v3 is allowed.  Cheers, Dani
SNMP v3