Thanks Luke!
No offense, but video encoding is nothing compared to FSX with 9+ years of high-res, payware, addons running. I also work with video and even though I'm primarily a still-life photographer, I use video editing techniques and software for my drone platform. I have a good idea of how much power video software can pull.
However, I had thousands of dollars invested in addons for FSX. When you're flying 250 feet AGL at .9 mach over land and scenery addons with 5m mesh, Orbx Global, vector, OpenLC, etc., in a Milviz F4J, your CPU better be up to the task or you'll crash the system and/or the sim's platform inside of 5 seconds, guaranteed.
The MS Dream Team did an amazing job with FSX. Compared to FS 2002 or 2009, FSX was an almost new approach. You're speaking to someone who literally learned how to build more and more powerful computers (and the most extreme overclocking tricks) just so that I could keep it running the kind of coding that was a well known nightmare for most FSX computers, (no store bought system could run the FSX platform I'm talking about).
This fact is no secret and you can find a lot about it very easily. When Lockheed Martin bought the FSX platform from MS, they began with FSX as the foundation for P3D. Then, they began recoding it with each new P3D upgrade version. I don't know how far they got by now, but I'm guessing they've gone a long way.
So, the FSX sim platform on its own isn't that bad, but as a hardcore Flight Sim hobbyist, I can say that we never flew FSX without the highest resolution addons available for Air, land & sea. The FSX sim hobbyist like myself had installed on our computers, looked nothing like the FSX 'out of the box':pilot:.
FWIW
PS It's really good to know that Windows 10 can run FSX. If true, and if it can run without any limitation regarding the 3rd party addons, I'll be installing it back onto my other computer!