You need to provide system specifications to even hope for a helpful answer.
Given that you've done a physical move, there are two things to check right away:
1) Are all the power connectors secure?
2) What is the room temperature, and if it's high (no A/C), what kind of ventilation do you have in the case?
3) As time as has passed, are you comparing the same games, or new games, which might perform worse simply by virtue of being new and more demanding?