Reality is far from what you'd expect. There isn't any course in college where you get quizzed on "What's the best CPU?" or "What's the best PC build under $XXXX money?" LOL
In computer science classes you learn how to code using linux or ssh in C++ and other programming languages. It is very basic. Basically the intro to it is what is a CPU, what kinds of memory are there, what is binary, assembly language, etc. Very basic. You won't need a blazing fast computer for comp sci as the software you will use is very basic, nothing but text (no GUIs).
Its pretty funny though, a lot of the professors you might take don't know much about video cards etc other than the basic things. They aren't into Intel or AMD, just X86 and the other...