Prime95 torture test, it'll run the cpu at 100% load and give it a true test for how good the cooler keeps the temperature, it'll test the CPU for sure. It is also good to test how good the overclock is, if it was not good, the screen will flicker and your computer may crash, but at 4.6Ghz, you should be fine.
For reference, I have a Intel i7 4930k running @ 4.9GHz, cooled by a Noctua NH-D14 SE2011, temps never go above 70 degrees, quite good indeed, great to see how your will perform.