what is the best monitor tools for measurement SMs ?

I want to measure latency and Throughput of SMs.What do you guys think which open source/freeware tools that make you satisfied and easy to do the report for manager ??? :wink:

There are a few of them out there - try Google. There are also a number of posts on here about this topic. Some have recommended Cactii (sp) or JFFNMS (Just For Fun NEtwork Management System). Lots of people also just use MRTG just fine.