2 questions about hard drive and ps3 hard drive space.

Hi so you know I made a post bout my laptop falling and I have finally thought about changing the hard drive except will a 160GB HD(how much is 160GB I know the numbers aren’t exact so how much space will I have left to use) be enough because I barely install anything besides my itunes and some software not much use and also does this mean I used 91GB out of 232GB or only 91GB left of space?
Answer #1
Get yourself an External 2-3 terabyte Drive
Or an Internal SATA 2 terrabit drive
Plug & Play..
They are pretty cheap at the moment
1 byte = 8 bits
1 kilobyte (K / Kb) = 2^10 bytes = 1,024 bytes
1 megabyte (M / MB) = 2^20 bytes = 1,048,576 bytes
1 gigabyte (G / GB) = 2^30 bytes = 1,073,741,824 bytes
1 terabyte (T / TB) = 2^40 bytes = 1,099,511,627,776 bytes
1 petabyte (P / PB) = 2^50 bytes = 1,125,899,906,842,624 bytes
1 exabyte (E / EB) = 2^60 bytes = 1,152,921,504,606,846,976 bytes (My wish 4 externals..)
OR U could buy DDD discs and put all junk on them.
Answer #2
Get yourself an External 2-3 terabyte Drive
Or an Internal SATA 2 terrabit drive
Plug & Play..I wish I could but I just don’t have any money right now for that so just making due with a low hard drive for now that is why I am asking about the hard drive.
Answer #3
How come my other hard drive connectors has an extra 4 pin but my laptop hard drive doesn’t have that 4 pin?

You see the front 2 hard drives that have 4 pins but my laptop HD doesn’t have a 4 pin. Both of the HD that has the extra 4 pins don’t work keeps giving me error maybe because I can’t connect the 4 extra pins so what do I do are all HD like this and did HP make a special sata HD so I can’t change?