Is there any loss of functionality if I disable snmp on HP SIM?
Yes there is a loss of detail and infomation provided by the Insight Agents. The newer PSP's like 8.15 can use WBEM instead of SNMP. Install PSP 8.15 on your ProLiants, login to SMH (Sys Mgmt Homepage), Settings, select data source of WBEM instead of SNMP.
WBEM is more secure then SNMP.