I have an 2008 unibody with a seagate 500gb momentus Hardrive in it already. I think its going bad because when apple ran a diagnostic there was a yellow yield sign. I am going to upgrade and get an optibay to replace super drive. I am confuse on the route I should go. Here are my options. any help is appreciated. 1st option samsung 256gb ssd + 750gb wd scorpio black hd. 2nd option= more room, cost lest. momentus xt 500gb sdd + 750gb wd scorpio black hd.