For higher clocks on Pascal, you have to keep the GPU cooler. Every 10-12c or so, there's a "layer" there when boost 3.0 will try to lower frequency / voltage to keep the card cool. Knowing where those are for your GPU pretty critical so you can try to avoid them with custom fan curves, or...
The cooler the core runs, the higher it'll be able to boost. With boost 3.0, the card will either drop frequency or drop voltage to help keep the core temps down....this happens about every 10c or so. I've seen it at work with core temps as low as 15c (coolant temps at -6c)....
The best way...
Maybe you should just stop posting on threads about benchmark scores, instead of posting 800 different times crying about those that do.
Just a thought... /smack
Use the voltage / frequency curve. You'll get a lot better results than with just using the offset method. Trick is just to keep the temps as low as possible.
I hate how expensive GPU blocks are, but.....sometimes you get really lucky. EVGA tends to use the same pcb layout quite often, especially for the Classy. The 780 / 980ti and now the 1080 Classy have all used the same block.
I usually set an offset just a little lower than the clock I'm trying to achieve, then move the point for the voltage up to the frequency of your target clock. Keep GPUz open and watch the PerfCap Reason Line. At some point, you'll hit the power limit (that's green, indicated by PWR)...at that...