Even though I don't recommend overclocking a laptop video card since they tend to run hot to begin with which will only shorten the life span of the hardware.
As stated above no one can tell you what your specific card will clock to as even the exact system and card will overclock differently.
Since the test is grayed out in Evga's Precision it makes me think their trying to tell you something like don't overclock this cause we won't even allow you to test it.
Their is MSI Afterburner which allows you to do the same things like change the fan speed and shader , memory clock. core clock and even the voltage. With several areas to store settings, yet still no way to test them except you also get MSI Kombuster which allows you to run benchmarks and stability tests. Which will show you any ganes you have achivded.
I have attached the program scanned with MSE no viruses found Attachment 131388
As mentioned above about the only thing you can do is to raise the levels up a little bit at a time till you find the threshold, then back them down a couple of notches. Once again I don't recommend overclocking a laptop graphics card. risk verse reward just isn't worth it. IMO. Fabe