Note: The fps above is the average fps that means if you have 100fps avg you will have approximately 60fps min.
Unless you have a crt or a 120hz lcd no monitor can display more than 60 to 70 max.Also, my monitor is getting on a bit and can't display too much fps.
How much the human eye can tell is down to the person, how much difference changing between 60 and 60+ the eye can tell is a different matter.