Originally Posted by
meganova
On your GSdx settings, change the Adapter to your graphic card (NVIDIA GeForce GTX 660 Ti), and the Renderer to Direct3D 11 (Hardware).
Make sure Native resolution box is checked when changing to the above settings. Uncheck the HW Hacks box as well.
Run the game, and see if there any differences. Use the ingame save btw, not the savestate when loading.
If not, try using different Speedhack preset (e.g set it to 3, run the game with/without MTVU box checked)
Switch back to Software mode if you having problem viewing the animated cutscene or mission briefing (toggle it by pressing F9)
Also, its a known issue that the game will lag if there are too many enemies on the screen (e.g Dynasty Warrior), regardless of whether you have good spec or not.