PlayStation 2 Emulator laggy

I just downloaded a PlayStation 2 emulator for my laptop. Tried to play Need for speed underground 2 and the cut scenes where fine but the game play was really slow around 8 frames per second. Any ideas

Laptop Specs

  • 12GB RAM
  • Inter Core i7-4710MQ CPU @ 2.50GHz 2.50GHz
  • Nvidia Geforce

This topic belongs on a totally different website. This is for Unity3D, not emulators.