who hit harder tyson or foreman?

[nomadman]

Foreman's kayo of Frazier was more impressive than every Tyson knockout combined.

From a resume POV sure, but Foreman had to put down Frazier down six times and the ref stepped in to call a halt to the contest with Frazier still on his feet. Foreman's most impressive knockout is still the Moorer one, and Moorer's chin was never ranked among his strongest traits.

[Clyde Barrow]

Foreman is a stronger puncher than Tyson. Mike makes up for that with handspeed to compliment his power though.