Dear obsidian support,
I don't know if you are aware of this issue but many users have problems with non-performance related constant stuttering in game. I have a strong rig (i7-4790K, GTX980, 16GB RAM) but I experience framedrops to 6FPS every couple of seconds - even the game is paused! I observed that the time interval between spikes depends on actual refresh rate. For example if I turn off v-sync the game is running at 150FPS and I have 160ms spikes every 5 second (look at the attachment). If I turn on v-sync the game is running 75FPS and those spikes are there every 20s. Capped at 30FPS the time between spikes is around 50 seconds. This is very strange and I would like if someone from developers can look at this issue as it completely ruin the game experience. Otherwise the game runs pretty smooth but this is not acceptable and very annoying.
Don't hesitate to contact me if you need further assistance.