This is well know since the beginning of elliptic curve usage in crypto.
But we count the number of group operation really performed (not the size of the range divided by time).

For instance in my BTCollider which use the DP method (also in O(sqrt(n))), I get 27.9 Mips (GeForce GTX 1050 Ti) for 80bit collision search. That means that I really compute 27.9M group operation and hash per second. It solves 80bit collision in 14h30 (in average). Note that in that case, it have to compute an EC mult for each group operation.

https://github.com/JeanLucPons/BTCCollider