Ok thanks. Can that help the game?
It may help, you will want to monitor your CPU/GPU & memory usage while gaming and note what they are during those dips and do this before buying anything as it may be something else causing that issue.
What resolution, refresh rate & graphic settings are your playing at?
I can't currently access Steam but isn't RUST still a Early Access game? If so I wouldn't expect the best performance on it since the game is still being worked on and your parts are on the lower end but adjusting the settings could minimize the dips.