See the following wiki articles, some of which were written by core developers like James Turner (leading core developer):
http://wiki.flightgear.org/Distributed_ ... FlightGearhttp://wiki.flightgear.org/Distributed_ ... Simulationhttp://wiki.flightgear.org/Modularizing ... FlightGearRegarding compilation of Nasal, feel free to search the forum for "llvm + nasal":
search.php?st=0&sk=t&sd=d&sr=posts&keywords=llvm+nasalSpeaking in general, compilation/interpretation is not the bottleneck for the time being.
Regarding the AI component, see:
http://wiki.flightgear.org/FGTrafficRegarding OSG concurrency, there is too much legacy OpenGL code in FG which would need to be phased out, also the current viewer setup/architecture isn't prepared for additional concurrency, the project would need to adopt/switch to PagedLOD and CompositeViewer:
http://wiki.flightgear.org/PagedLODhttp://wiki.flightgear.org/CompositeViewer_SupportSpeaking in general, the FlightGear project has been hoping to adopt HLA/RTI for better modularization and concurrency support using processes instead of threads:
http://wiki.flightgear.org/High-Level_ArchitectureI don't think there is a Vulcan related article for the time being, but as you can surely see by now many of the people "in the know" have already discussed some of FlightGear's actual shortcomings, including ways to possibly address those over time
It would seem like a good idea to read up on what's been previously said in the context of the performance debate.
You could also create some of your own benchmarks to help with testing/profiling FlightGear so that actual hot spots can be identified:
http://wiki.flightgear.org/Testinghttp://wiki.flightgear.org/FlightGear_Benchmarkhttp://wiki.flightgear.org/Built-in_Profilerhttp://wiki.flightgear.org/Howto:Use_the_system_monitorhttp://wiki.flightgear.org/OSG_on_screen_statsAs you can see, there are plenty of resources to form an informed opinion about FlightGear's performance and issues related to that.
Admittedly, it may take a while to look up what's been previously said and done in the context of this discussion, but it will at least help you get a more comprehensive picture of all the variables involved in the equation.
The other issue being, that it simply isn't realistic to expect that a single person is going to single-handedly re-architecture FlightGear as a whole based on random ideas like those tossed around in your previous posting. The OSG/HLA debate/effort have been ongoing for over 10 years meanwhile. Also, the GUI2Qt transition is another project where the timescale and expectations has been massively undeestimated by some folks.