Currently the formula is:
(((x / (cap ^ 0.995)) + 0.085) * 400000) if x ≤ cap
(((x / (cap ^ 0.995)) + 0.085) * 400000 * 1.5) if x > cap
Which means that if you are below 810 CP, you will gain xp fairly quickly, but once you are 810, the next point 811, will required significantly more xp because of the added 1.5x multiplier if you're over the cap.
Will this 1.5x added multiplier be removed? I know before the multiplier was 3x. You were penalized 3 times more xp for a single champion point.