Data-dumping FS performance numbers?

Hi - I don't know if this is the right forum, but I'm interested in finding out how one might go about dumping certain data from FS over time - For example, I'd like to open a flight saved enroute, let it go on autopilot, and record the frame rate every 30 seconds.I don't know what internal data may exist that isn't normally viewable.The main reason for this is that I'm experiencing gradual slowdown (I'm on an older system) until even opening a menu while in-flight takes 45 seconds.This way, I could let the same flight run with different setting and at least try to observe performance differences. Optimally, if the data dump could be formatted into a spreadsheet it may become very obvious (on any system) when and where resources are getting taxed in a way that the general hands-on experience of performance degradation may not be.Thanks,Andrew