Dear,

I think you will see that the number of bytes saved will be equal to your stack depth. The remaining bytes will not be saved due to stack overflow.

As for the exact timing, see the post from Steve Barnes and Pravin Pawar and the tutorial on the left. Check the number of cycles you need for each instruction. Knowing that you need x clock-periods/machine cycle, you should be able to figure out how long it takes.

rgds
Patrick