I have 3 instances on HM running on the same server each running checks on about 225 hosts at the same time. The server is rebooting itself after memory dumping after looking in the event log its blaming it on system resources.Its q.quick with 660mb. Could Host monitor cause such an impact?
I don't think its HostMonitor's fault. We spent a lot of time to find all resource leakage. However will be better if you will check this by yourself, you can use standard Task Manager to check how much resources HostMonitor uses.
BTW: Why you start 3 copies of HostMonitor?