Rob posted this interesting and helpful message earlier today. We moved it to the FSX forum where OOM's are even more frequently discussed than in any other forum. Hope you enjoy the read and that you can put Rob's program to work for you.
I am posting this in the PMDG 777 forum, because there is no doubt that the 777 has a large VAS footprint, and hence users of this aircraft addon are most exposed to OOMs if their setup is not optimised, and they are also loading heavy add-on sceneries. So reports of OOMs are always surfacing here, a recent topic being an example, with the usual mix of "I have no problem", "I have serious problems", and snide comments suggesting that PMDG would hide a fault in their product.
At the outset, let me say that there is nothing wrong with the PMDG 777. It is an intensive simulation (we wanted all those systems and features!). The Lua script I make available here proves this statement beyond doubt (if you do not want to try it out youself at least look at the examples I provide and Think! You should see why I can make such a definite statement). I have yet to experience an OOM myself even on long flights (14.5 hours max so far).
Many users monitor their VAS-usage visually, using Process Explorer or FSUIPC. This is somewhat of a subjective approach, and when an OOM happens its too late to see exactly what the VAS value was, where you were, flight parameters and environmental data at the time. This results in some rather generalized statements about the event.
As a scientist I prefer to work with hard data and facts.
So I have written an FSPUIC LUA script that logs VAS usage (used and remaining), together with other flight parameters (a simple ACARS reporting system) to a .csv file. This enables one to do post-flight analysis using a spreadsheet (checking the numbers and phase of flight), and or/to plot informative graphs. It also allows mapping of the flight path and data in Google Earth (via a kml converter). Flight parameters at any point can be viewed by clicking on a POI point on the flight line / path.
The .csv files are small (.kml even smaller). The LUA does not use FSX VAS, or affect FPS while running.
My hope is that those who continue to suffer OOMs will use this tool, create .kml files of the problem flight, and share these when asking for help. Other users can see exactly where the user was flying (and may be able to suspect use of certain scenery add-ons), what the plane was doing, as well as environmental conditions (winds, clouds, turbulence) at the time VAS got out of control.
Of course users should also be very specific about their FSX settings and scenery add-ons in use at the time
I have designed the LUA reporting script so the the data in the .csv file contains the same information, and is in roughly the same order, as a PFPX OFP page. So besides logging VAS, you have a digital record of the actual flight to compare agains the OFP estimates (timing, waypoints, winds, temps, fuel remaining).
NOTE: you must have a registered copy of Pete Dowson's FSUIPC to be able to use this tool.
A zip file containing the LUA script, User Manual (Installation and usage instructions, analysis examples, and tips on avioding OOMs - PDF) and my system and FSX settings (PDF) can be downloaded here;
An example of a close shave with OOM, and how logged data can be mapped, is here;
You can read the post and forum messages on this topic here.