Was browsing the ARK forums and happened to find this thread that explained how to get much better performance out of ARK. The thread also contains common issues with ARK in general (crashes, etc), so if you are having problems as of late then it may help you.
Original thread here
Steam thread here
Below is the list of commands that has helped me the most, went from having 45 - 55 frames to 60 -70 frames.
Note: To find out what all the commands mean and for more instructions to improve performance go to the steam thread listed above.