Open a CLI and do:

sudo nvidia-xconfig

Then:

sudo nvidia-settings

Set your screen resolution and refresh rate in the Xserver settings (I set mine to 1920x1200 @60hz) and save it to xorg.conf

Then do:

sudo nano /etc/X11/xorg.conf

Edit the device section thusly:

Section "Device"
Identifier "Device0"
Driver "nvidia"
VendorName "NVIDIA Corporation"
BoardName "GeForce GTX 650"
Option "RegistryDwords" "PerfLevelSrc=0x2222"
Option "TripleBuffer" "True"
EndSection

This sets the card to performance mode and enables triple buffering.

In nvidia-settings/OpenGL set:

Sync to Vblank
Allow Flipping
Use Conformant Texture Clamping

Save your configuration and restart the X-server.