Just sharing this in case it helps anyone. I updated to the current Win 10 build through Insider updates, and after RTM I noticed that my fan was running a LOT, when it rarely ran before, and it was running because my SP3 was constantly running very warm. Which was also unusual, my SP3 almost always runs mostly cool. If by killing certain services and processes I was able to get the thing calmed down again, as soon as I walked away and left the thing idle again for 5 minutes-ish or more, it'd be hot again and fan running. Did a bunch of troubleshooting, watching different services, CPU, resource monitor, uninstalling and reinstalling drivers, etc etc. Finally shut Cortana off, and the whole machine is happy again. I can't explain it and I don't really care what about Cortana was messing with my SP3. I rarely used it (although I do want to use it more) and so I am happy just to have my machine running cool again. I'm planning on doing a clean install in the next 3 or 4 weeks, and will use Cortana again at that point and see what happens. More than likely, something is just buggered with my current build. Just passing this on in case it helps anyone else.