Please give us more information as to your Computer Specs
The emulator in question will lag anyway for some games though, it is still in development or was in mid development if development has stopped on it
Anotherwords it's not optimised for ever game or even playable with every game
... before I forget, a sample of what you have been trying to play aswell will be handy to those wishing to help you
P.S. I removed the Poll as it had little to do with emulation help, it was more of a general gaming thing to be honest, no biggy just not for this section