Yup, I have voltmoded it. It is an A2 revision and requires a bit more voltage than A3 revisions. All GTX are supposed to run at 1.30volts stock and Ultra's at 1.35V. Memory voltage is supposed to be at 1.95volts. Mine though was 1.28v at idle and 1.23 at load. Now it is 1.39v idle and 1.36v load. You can find guides all over the net on how to do it. The voltage then is measured at another point on the PCB. My memory was at 1.91 and I raised its voltage to 1.95 exactly. Mine has Samsung 1ns chips and they don't gain anything over 1.95v. Just heat. However, if your board has Hynix chips it can benefit from even higher voltage. Whatever you do, don't mess with Vdroop mods. The same applies to your motherboard. There is an Intel paper describing exactly what Vdrrop is supposed to do and you shouldn't mess with it.
Last point, don't raise your GTX voltage without proper cooling. Stock nVidia cooler is not suitable.