I would also add that the 120 GB should be good for me for now. Im justing using this for pictures, word processing, internet, and Ill probably need to use bootcamp or Fusion for windows use. Im not sure what the cache memory is? What is that and how does it make a difference between the two units?
Cache memory is memory that sits right on the CPU. It is very very small, is in ingrained into the chip. This memory allows the CPU to store data close at hand for easy access. The more it has there, the faster it can work certain kinds of tasks.
The equivalent my CS prof gave was this
Onboard chip memory = accessing your brains memory
RAM = accessing data that takes a 3 hour plane trip to get to
Hard Drive = accessing data on the planet* Pluto
That is why you want more RAM, and don't want your computer using the HD to store "temporary" data, and you want to onboard cache to be storing information, and not your RAM.
But, all of these are task depended. No reason to have a formula one car if all you do is drive around the wal-mart parking lot
I'm here for followup questions!
~Tyler
*yes, it's a planet, and it always will be a planet, B**ch!