As a Computer Engineering student, it is better if you buy an assembled PC, and there are 3 main reasons why you should buy only the parts of a PC.
- You will be able to choose your desired Graphics Card, with you own combination from you Motherboard and your Processor. In this case, because Intel I7 and I5 does only simple job (processing the data). I would rather choose the core I5 because it is much cheaper and 3.3ghz clockrate is still the same. Unless your are working with a lot of projects. Example is Mining BTC.
- If you buy a new PC - then everything you see is already fixed. You cannot chose your desired type of SDRAM slot.
- More Options - unless you are buying a laptop which they already built it for simple use. PC has more options, you can either dismantle other parts like your (Main Memory) upgrade it to much bigger Memory. It is that simple.