The 'Kepler' GPUs from Nvidia perform really well, even at increased clocks speeds they stay quite cool - a perfect behavior when it comes to overclocking and improving the performance.
Unfortunately the mobile GPUs suffer from an artificial +135MHz core overclocking limit, so you can't go higher by using tools like Nvidia Inspector and similar.
The modified VBIOS files listed here have this limit unlocked, some have increased stock clocks or tweaked voltages.
I recommend flashing under DOS using nvflash
In case you want to buy me a beer
Thanks and cheers!