Hi
look at that link
http://www.solarwinds.com/documentation/Orion/docs/ScalabilityEngineGuidelines.pdf
~12k elements at standard polling frequencies:
Node and interface up/down: 2 minutes/poll
Node statistics: 10 minutes/poll
Interface statistics: 9 minutes/poll
25-50 concurrent Orion Web Console users
SNMP Traps: ~500 messages per second (~1.8 million messages/hr)
Syslog: 700-1k messages/second (2.5 - 3.6 million messages/hr)
Note: If you are monitoring more than ~100,000 elements,
