Hi rocketjetz.
It depends on what you want to monitor and what you mean when you talk about "latency" (e.g.: disk, network).
The Windows Performance Monitor is a tool that administrators can use to examine how programs running on their computers affect the computer's performance; Process Monitor looks at and displays in real time the file system, registry and network
activity.
Both of them could be useful, but it still depends on the exact metrics you need to measure: there are many counters available in Performance Monitor.
Bye.
Luigi Bruno
MCP, MOS, MTA, MCTS, MCSA, MCSE