They use the same engine.
The difference is that the maps in Recharged is bigger and more detailed. So the are more demanding graphics-wise.
You can try to run Recharged at lower resolution to get better performance.
In windows you can set the resolution by using command line parameters as described in the manual:
https://drive.google.com/file/d/0BwSDHIR7yDwSelpqMlhaSzZOa1k/view?usp=sharing