go as fast as you feel like. get Unigine Valley 1.0 3D Benchmark. You can visit their site and choose a mirror for the Download, I like TechPowerUp For this one.
http://www.techpowerup.com/downloads/2208/unigine-valley-benchmark-1-0/
Also there are some other tools which you may or may not have. that is: 1 MSI Afterburner Version 4.0.0 Final/Stable, or 4.1.0. (Note MSI AB install includes RTSS) or EVGA Precision 16 (5.2.7.0) 2 GPU-Z. And that is the essential list, feel free to add anything you feel should help.
Ok Firstly Raise Power Target and temp target. It should go up to 125% on Maxwell. Then the rest is actually quite trivial. Keep increasing GPU Core Clock Speed and re running Valley 1.0. Raise voltages to prevent...