Great! Where do I find a compatibility list for nVidia cards? Curious to know whether my spare GTX980 can do VP9 and VP9 10-bit or not.
Edit: Just checked the Wikipedia link and it looks like there is no luck for my spare GTX980... It has to be my GTX1080 instead then..
Nowadays Youtube widely uses VP9 and is rumoured to end H264 soon..
Yeah you need Pascal / Feature Set F onwards afaik. You can download and run Emby as a portable app (check the website) which would give you chance to quickly check what your system supports and how it performs. There's no issues doing that on a live system alongside Plex, for example, so nothing to lose. YouTube does indeed serve VP9 (except to Safari/iOS) by default. If your card/CPU don't support it in hardware you can run the H264ify extension to force H264 instead. That can be useful on low end systems, or portable systems (i.e. hardware acceleration uses much less battery than CPU decoding of VP9 in the browser).
Back on topic, your 1080 should support VP9 without issues. Using Emby would then allow you some breathing space without having to immediately upgrade your CPU just for transcoding. As I said, just run the portable instance and see how you like it. It has more features than Plex and is easy to set up.