Speed comparison between vector and 2*2 array
I'm refactoring someone else's code, and this code uses an underlying 1D vector to implement a 2D array. If the 2D arrays were variable in size, I'd leave it alone, but the sizes of these "arrays" are pretty much set in stone, so there's no problem changing them to straightforward 2D arrays (which I am aware are still 1D arrays in memory). Now, if I had the time, I'd do speed tests myself, but I am on a deadline, so I'm asking you experts' advice.
In a program that does several million iterations over these arrays (101 by 101 to be precise), would there be a significant speed gain if I switched from vectors to arrays?