On Sunday (yesterday), Hardware.info published an article on the frequency scaling using the most common and most exotic cooling methods. Going from air cooling over water cooling, to cascade and eventually liquid nitrogen, the Dutch technology website finds out how much extra MHz you get out of your system as well as what the effect is on voltage scaling.
Using the Core i7 5960X processor, the maximum stable CPU frequency goes up from 4.6GHz on air cooling using 1.3V to 5.4GHz with liquid nitrogen using 1.65V. That's about 18% extra frequency. The performance as measure by Cinebench R15 went up from 20,08 points to 23,65 points, which is also about 18%. That's a pretty good deal! Almost 1:1 performance scaling with frequency.
Other interesting testing includes checking how the frequency scales with just the temperature as the voltage is kept at 1.3V. As it turns out, the frequency goes up to 5GHz from a default overclocking on air at 4.6GHz. Also, using liquid nitrogen the required voltage for running 4.6GHz is only 1.175V as opposed to 1.3V using air cooling.