I currently have a Macbook Pro MacBook Pro (15-inch, 2.53GHz, Mid 2009) MacBookPro5,4 Running with 8 gigs of ram. I used my friends mac air with a 160 ssd and 4 gigs or ram and it blew my mac out of the water. agreed it was much newer but still i wasnt expecting it to be such a night and day difference. Finally my question is!! Can my mac handle a SSD swap ( i believe so) i currently have a bootable USB of yosemite and ill time machine my mac as well. but what the factors for me to look for when purchasing the right ssd to not have and compatibly issues. Any and all replys are appreciate.. Hopefully not asking to much but what do i look for as far as the diameter of the hhd. Thanks in advance.