I currently dual boot Linux and Windows 10 on my desktop gaming system with a GTX 970 but find it a pain having to boot up Windows any time I want to play a game. I just bought a basic desktop to use as my Linux box, but now I'm interested in running my gaming PC headless just for Gamestream purposes. Has anybody here done this? Any tips or gotchas I should know in advance?
u/sikilikis is pretty bang on, disable your password on windows and set it to auto-login on boot. Windows scheduler can be used to open you steam and close programs like windows explorer. You may want to configure your PC's sleep setting to save power. In order to wake your computer up you could look into Wake on Lan solutions, there may be a BIOS option you can enable.
The other thing to consider is you will need some sort of dongle plugged into the display connector to make it think it has a monitor with X resolution!
Something like this:
HDMI Display Emulator Headless Adapter
Edit: Revised HDMI Headless Display Adapter for GameStream Use per /u/WhySheHateMe.
I'm doing this. It works OK I'd say 85% of the time. Sometimes you need to VNC in to shut down a misbehaving app, or just reboot the whole thing because it got cranky. You also need a $15 dongle to trick the video card.
Overall, it's not a bad setup, but it can be clunky at times.
Do you mean that you just want to turn on your windows machine and leave it on forever, only accessing it using Gamestream on your shield?
I've never run windows headless before so I don't know how flexible you can be. You probably have to have it not need a password when booting up and you want some programs to run on startup, like Steam and probably any remote desktop software you need (VNC for example). Maybe turn off things like automatic updates (both for steam and windows, or any other programs where it applies). Make sure a virus scanner won't bother you. And of course you would want to be ready with a monitor/keyboard/mouse in case something goes wrong.
Other then that I don't know any gotchas that might come up. I'm thinking of this as "its windows but you don't have any peripherals plugged in" when you might be looking for a more "real" headless solution.