Core i7 4790K OC at 4600 MHz 1.3 Volts

Now we up the ante. Understand that 1.3V and higher voltages are the levels where Haswell processors get into serious problems due to the aforementioned heat-spreader versus TIM design applied solution from Intel. We now set the Core i7 4790K @ 4600 MHz and apply 1.30 volts on the CPU while loading it with 100% stress for wPrime 1024M to run on all available CPU threads three times.

Core i7 4790K OC at 4600 MHz 1.3 Volts - IDLE 

Below, you can see the IDLE results with the Core i7 clocked at 4790K @ 4600 GHz with 1.30 volts on the CPU. Again, the results are the IDLE temperatures thus you are in your desktop doing pretty much nothing. 

Core i7 4790K OC at 4600 MHz 1.3 Volts LOAD

Now we'll be testing the temperatures under fully threaded stress. If we set the overclock at 4600 MHz and configure CPU Voltage at 1.3V, these are the results.  

 
The temps normally rise above and beyond 90 Degrees C for a lot of heatpipe based coolers, which is a definitive no-no. As you can see, we have dangerous temperatures for most coolers. Very few coolers and kits can actually manage a Core i7 4970K @ 1.3+ Volts / 4600+ MHz temperature wise well enough.
  

We cannot use this 120W cooler for processor tweaking with added voltage, but hey that was to be expected. 

Core i7 4790K and 1.3 Volts in the CPU (we measure package temperature) - that is a definitive NO.