How do I initialize a multi-dimensional array of a primitive type as fast as possible?

I am stuck with using multi-dimensional arrays. My problem is performance. The following routine initializes a 100x100 array in approx. 500 ticks. Removing the int.MaxValue initialization results in approx. 180 ticks just for the looping. Approximately 100 ticks to create the array without looping and without initializing to int.MaxValue. Routines similiar to this are called a few tens-of-thousands to several million times.

I am open to suggestions on how to optimize this non-default initialization of an array. One idea I had is to use a smaller primitive type when available. For instance, using byte instead of int, saves 100 ticks. I would be happy with this, but I am hoping that I don't have to change the primitive data type.

    public int[,] CreateArray(Size size) {
        int[,] array = new int[size.Width, size.Height];
        for (int x = 0; x < size.Width; x++) {
            for (int y = 0; y < size.Height; y++) {
                array[x, y] = int.MaxValue;
            }
        }
        return array;
    }