It’s meaningless and impossible to measure.
If anyone is trying to base their decision on which very top school to attend based on what random internet people think of relative prestige then they’re doing it wrong. And being in Silicon Valley might not be a selling point for someone not interested in all that (IE most students).
Look at how the programs are structured. What differences are there overall? Any difference in offerings/requirements for the majors you’re interested in? Is location important and which do you prefer? What about cost? Have you visited each?