Good news AMD CPU fans, Feral Interactive has released a patch for Alien Isolation which should help you a little bit. There's other fixes too.
Changelog (Sent to us by Feral)
* Improves Mouse sensitivity issues seen when using certain Linux distro's
* Fixes occasional launch issue when running the game on an external drive (OS X)
* Improves performance on AMD CPUs (Linux)
I'm still not brave enough to venture back in just yet, but I will get around to it and I will likely livestream it when I do!
If you still haven't picked it up, why not?