The main GPU is not working at 100%, what can be done?

disable any Windows visualization effects via system properties > advanced > settings > adjust for best performance
I get
Jul 25 21:46:41 minera4 cpuminer[2945]: GPU #0: GeForce GTX 750, 2118 khash/s
Jul 25 21:46:41 minera4 cpuminer[2945]: GPU #1: GeForce GTX 750, 2130 khash/s
on a 750 NON-TI, with a bit of overclocking.
No did not alter bios.