A:Answer To be honest, I don't know for sure and cannot find a definitive answer. Based on that I assume it is a 60hz true refresh rate. Otherwise, Vizio would be printing in the largest font possible 'TRUE 120HZ REFRESH RATE" not 120hz effective refresh rate. That being said after watching the set for the last few weeks with all types of fast motion I personally have not noticed any motion blurring. In a nutshell, I find the set to be very good (on par with any other 4k TV I have seen) and for a very good price. I am very pleased with my purchase.