Sorry Oliver, but you said that FSX calculates the clouds but ASN does that, it just sends the data to FSX to render. This is why you can actually get better frames if you use an external weather program.

 

I used REX 512bit textures and agree they look good, but I found that FEX at the same resolution, in my opinion look better.

 

There are a few add-ons that people pump up the texture size, that look just as good. Orbx Global, Vector and LC can be installed and if you lower the quality along with the Autogen quantity will help with VAS.

 

 

...so ASN does not actually add to the VAS, well it does with the sound module but that's different....

 

Well, even that is an external .exe process (as_audio.exe), so no VAS contribution on that either. The only thing ASN actually adds to fsx VAS (through its radar modules) is less than 20 MB (worst case scenario with an extreme cloud draw distance set to 200). But of course this doesn't count the number of clouds that have to be drawn by fsx itself as mentioned previously. 

If you use AI, get a program called AISIDSTAR, this will take control of AI in the air, this helps release FSX of such a load.

 

If the Ai aircraft are controlled via positioning through simconnect, then the load is increased considerably. If the Ai aircraft are controlled via waypoint updates, then FSX is still consuming more resources as it still flies the planes but now receives updates to all the courses.

VMMAP from SysInternals will tell you all you want to know about the usage of virtual memory used by a process. It will show, for example, the combination of virtual memory used by FSX and ASN.